diff --git a/include/uv.h b/include/uv.h
index cde05cb9b..4ee43bce5 100644
--- a/include/uv.h
+++ b/include/uv.h
@@ -361,18 +361,22 @@ typedef void (*uv_alloc_cb)(uv_handle_t* handle,
  * Trying to read from the stream again is undefined.
  *
  * The callee is responsible for freeing the buffer, libuv does not reuse it.
- * The buffer may be a null buffer (where buf.base=NULL and buf.len=0) on EOF
- * or error.
+ * The buffer may be a null buffer (where buf->base=NULL and buf->len=0) on
+ * EOF or error.
  */
-typedef void (*uv_read_cb)(uv_stream_t* stream, ssize_t nread, uv_buf_t buf);
+typedef void (*uv_read_cb)(uv_stream_t* stream,
+                           ssize_t nread,
+                           const uv_buf_t* buf);
 
 /*
  * Just like the uv_read_cb except that if the pending parameter is true
  * then you can use uv_accept() to pull the new handle into the process.
  * If no handle is pending then pending will be UV_UNKNOWN_HANDLE.
  */
-typedef void (*uv_read2_cb)(uv_pipe_t* pipe, ssize_t nread, uv_buf_t buf,
-    uv_handle_type pending);
+typedef void (*uv_read2_cb)(uv_pipe_t* pipe,
+                            ssize_t nread,
+                            const uv_buf_t* buf,
+                            uv_handle_type pending);
 
 typedef void (*uv_write_cb)(uv_write_t* req, int status);
 typedef void (*uv_connect_cb)(uv_connect_t* req, int status);
diff --git a/src/unix/stream.c b/src/unix/stream.c
index ab030a795..aa49c21bf 100644
--- a/src/unix/stream.c
+++ b/src/unix/stream.c
@@ -938,7 +938,7 @@ static uv_handle_type uv__handle_type(int fd) {
 
 static void uv__stream_read_cb(uv_stream_t* stream,
                                int status,
-                               uv_buf_t buf,
+                               const uv_buf_t* buf,
                                uv_handle_type type) {
   if (stream->read_cb != NULL)
     stream->read_cb(stream, status, buf);
@@ -947,7 +947,7 @@ static void uv__stream_read_cb(uv_stream_t* stream,
 }
 
 
-static void uv__stream_eof(uv_stream_t* stream, uv_buf_t buf) {
+static void uv__stream_eof(uv_stream_t* stream, const uv_buf_t* buf) {
   stream->flags |= UV_STREAM_READ_EOF;
   uv__io_stop(stream->loop, &stream->io_watcher, UV__POLLIN);
   if (!uv__io_active(&stream->io_watcher, UV__POLLOUT))
@@ -982,7 +982,7 @@ static void uv__read(uv_stream_t* stream) {
     stream->alloc_cb((uv_handle_t*)stream, 64 * 1024, &buf);
     if (buf.len == 0) {
       /* User indicates it can't or won't handle the read. */
-      uv__stream_read_cb(stream, UV_ENOBUFS, buf, UV_UNKNOWN_HANDLE);
+      uv__stream_read_cb(stream, UV_ENOBUFS, &buf, UV_UNKNOWN_HANDLE);
       return;
     }
 
@@ -1019,23 +1019,23 @@ static void uv__read(uv_stream_t* stream) {
         if (stream->flags & UV_STREAM_READING) {
           uv__io_start(stream->loop, &stream->io_watcher, UV__POLLIN);
         }
-        uv__stream_read_cb(stream, 0, buf, UV_UNKNOWN_HANDLE);
+        uv__stream_read_cb(stream, 0, &buf, UV_UNKNOWN_HANDLE);
       } else {
         /* Error. User should call uv_close(). */
-        uv__stream_read_cb(stream, -errno, buf, UV_UNKNOWN_HANDLE);
+        uv__stream_read_cb(stream, -errno, &buf, UV_UNKNOWN_HANDLE);
         assert(!uv__io_active(&stream->io_watcher, UV__POLLIN) &&
                "stream->read_cb(status=-1) did not call uv_close()");
       }
       return;
     } else if (nread == 0) {
-      uv__stream_eof(stream, buf);
+      uv__stream_eof(stream, &buf);
       return;
     } else {
       /* Successful read */
       ssize_t buflen = buf.len;
 
       if (stream->read_cb) {
-        stream->read_cb(stream, nread, buf);
+        stream->read_cb(stream, nread, &buf);
       } else {
         assert(stream->read2_cb);
 
@@ -1070,10 +1070,12 @@ static void uv__read(uv_stream_t* stream) {
 
 
         if (stream->accepted_fd >= 0) {
-          stream->read2_cb((uv_pipe_t*)stream, nread, buf,
-              uv__handle_type(stream->accepted_fd));
+          stream->read2_cb((uv_pipe_t*) stream,
+                           nread,
+                           &buf,
+                           uv__handle_type(stream->accepted_fd));
         } else {
-          stream->read2_cb((uv_pipe_t*)stream, nread, buf, UV_UNKNOWN_HANDLE);
+          stream->read2_cb((uv_pipe_t*) stream, nread, &buf, UV_UNKNOWN_HANDLE);
         }
       }
 
@@ -1147,7 +1149,7 @@ static void uv__stream_io(uv_loop_t* loop, uv__io_t* w, unsigned int events) {
       (stream->flags & UV_STREAM_READ_PARTIAL) &&
       !(stream->flags & UV_STREAM_READ_EOF)) {
     uv_buf_t buf = { NULL, 0 };
-    uv__stream_eof(stream, buf);
+    uv__stream_eof(stream, &buf);
   }
 
   if (uv__stream_fd(stream) == -1)
diff --git a/src/win/pipe.c b/src/win/pipe.c
index 5e73cb9e2..09b59cc65 100644
--- a/src/win/pipe.c
+++ b/src/win/pipe.c
@@ -1296,9 +1296,9 @@ static void uv_pipe_read_eof(uv_loop_t* loop, uv_pipe_t* handle,
   uv_read_stop((uv_stream_t*) handle);
 
   if (handle->read2_cb) {
-    handle->read2_cb(handle, UV_EOF, uv_null_buf_, UV_UNKNOWN_HANDLE);
+    handle->read2_cb(handle, UV_EOF, &uv_null_buf_, UV_UNKNOWN_HANDLE);
   } else {
-    handle->read_cb((uv_stream_t*) handle, UV_EOF, uv_null_buf_);
+    handle->read_cb((uv_stream_t*) handle, UV_EOF, &uv_null_buf_);
   }
 }
 
@@ -1314,10 +1314,10 @@ static void uv_pipe_read_error(uv_loop_t* loop, uv_pipe_t* handle, int error,
   if (handle->read2_cb) {
     handle->read2_cb(handle,
                      uv_translate_sys_error(error),
-                     buf,
+                     &buf,
                      UV_UNKNOWN_HANDLE);
   } else {
-    handle->read_cb((uv_stream_t*)handle, uv_translate_sys_error(error), buf);
+    handle->read_cb((uv_stream_t*)handle, uv_translate_sys_error(error), &buf);
   }
 }
 
@@ -1432,9 +1432,9 @@ void uv_process_pipe_read_req(uv_loop_t* loop, uv_pipe_t* handle,
       handle->alloc_cb((uv_handle_t*) handle, avail, &buf);
       if (buf.len == 0) {
         if (handle->read2_cb) {
-          handle->read2_cb(handle, UV_ENOBUFS, buf, UV_UNKNOWN_HANDLE);
+          handle->read2_cb(handle, UV_ENOBUFS, &buf, UV_UNKNOWN_HANDLE);
         } else if (handle->read_cb) {
-          handle->read_cb((uv_stream_t*) handle, UV_ENOBUFS, buf);
+          handle->read_cb((uv_stream_t*) handle, UV_ENOBUFS, &buf);
         }
         break;
       }
@@ -1451,10 +1451,10 @@ void uv_process_pipe_read_req(uv_loop_t* loop, uv_pipe_t* handle,
           handle->remaining_ipc_rawdata_bytes =
             handle->remaining_ipc_rawdata_bytes - bytes;
           if (handle->read2_cb) {
-            handle->read2_cb(handle, bytes, buf,
+            handle->read2_cb(handle, bytes, &buf,
               handle->pending_ipc_info.socket_info ? UV_TCP : UV_UNKNOWN_HANDLE);
           } else if (handle->read_cb) {
-            handle->read_cb((uv_stream_t*)handle, bytes, buf);
+            handle->read_cb((uv_stream_t*)handle, bytes, &buf);
           }
 
           if (handle->pending_ipc_info.socket_info) {
@@ -1462,7 +1462,7 @@ void uv_process_pipe_read_req(uv_loop_t* loop, uv_pipe_t* handle,
             handle->pending_ipc_info.socket_info = NULL;
           }
         } else {
-          handle->read_cb((uv_stream_t*)handle, bytes, buf);
+          handle->read_cb((uv_stream_t*)handle, bytes, &buf);
         }
 
         /* Read again only if bytes == buf.len */
diff --git a/src/win/tcp.c b/src/win/tcp.c
index 7b653175b..7bc1a0244 100644
--- a/src/win/tcp.c
+++ b/src/win/tcp.c
@@ -436,7 +436,7 @@ static void uv_tcp_queue_read(uv_loop_t* loop, uv_tcp_t* handle) {
     handle->flags &= ~UV_HANDLE_ZERO_READ;
     handle->alloc_cb((uv_handle_t*) handle, 65536, &handle->read_buffer);
     if (handle->read_buffer.len == 0) {
-      handle->read_cb((uv_stream_t*) handle, UV_ENOBUFS, handle->read_buffer);
+      handle->read_cb((uv_stream_t*) handle, UV_ENOBUFS, &handle->read_buffer);
       return;
     }
     assert(handle->read_buffer.base != NULL);
@@ -916,7 +916,7 @@ void uv_process_tcp_read_req(uv_loop_t* loop, uv_tcp_t* handle,
 
       handle->read_cb((uv_stream_t*)handle,
                       uv_translate_sys_error(err),
-                      buf);
+                      &buf);
     }
   } else {
     if (!(handle->flags & UV_HANDLE_ZERO_READ)) {
@@ -925,7 +925,7 @@ void uv_process_tcp_read_req(uv_loop_t* loop, uv_tcp_t* handle,
         /* Successful read */
         handle->read_cb((uv_stream_t*)handle,
                         req->overlapped.InternalHigh,
-                        handle->read_buffer);
+                        &handle->read_buffer);
         /* Read again only if bytes == buf.len */
         if (req->overlapped.InternalHigh < handle->read_buffer.len) {
           goto done;
@@ -940,7 +940,7 @@ void uv_process_tcp_read_req(uv_loop_t* loop, uv_tcp_t* handle,
 
         buf.base = 0;
         buf.len = 0;
-        handle->read_cb((uv_stream_t*)handle, UV_EOF, handle->read_buffer);
+        handle->read_cb((uv_stream_t*)handle, UV_EOF, &handle->read_buffer);
         goto done;
       }
     }
@@ -949,7 +949,7 @@ void uv_process_tcp_read_req(uv_loop_t* loop, uv_tcp_t* handle,
     while (handle->flags & UV_HANDLE_READING) {
       handle->alloc_cb((uv_handle_t*) handle, 65536, &buf);
       if (buf.len == 0) {
-        handle->read_cb(handle, UV_ENOBUFS, buf);
+        handle->read_cb((uv_stream_t*) handle, UV_ENOBUFS, &buf);
         break;
       }
       assert(buf.base != NULL);
@@ -964,7 +964,7 @@ void uv_process_tcp_read_req(uv_loop_t* loop, uv_tcp_t* handle,
                   NULL) != SOCKET_ERROR) {
         if (bytes > 0) {
           /* Successful read */
-          handle->read_cb((uv_stream_t*)handle, bytes, buf);
+          handle->read_cb((uv_stream_t*)handle, bytes, &buf);
           /* Read again only if bytes == buf.len */
           if (bytes < buf.len) {
             break;
@@ -974,14 +974,14 @@ void uv_process_tcp_read_req(uv_loop_t* loop, uv_tcp_t* handle,
           handle->flags &= ~(UV_HANDLE_READING | UV_HANDLE_READABLE);
           DECREASE_ACTIVE_COUNT(loop, handle);
 
-          handle->read_cb((uv_stream_t*)handle, UV_EOF, buf);
+          handle->read_cb((uv_stream_t*)handle, UV_EOF, &buf);
           break;
         }
       } else {
         err = WSAGetLastError();
         if (err == WSAEWOULDBLOCK) {
           /* Read buffer was completely empty, report a 0-byte read. */
-          handle->read_cb((uv_stream_t*)handle, 0, buf);
+          handle->read_cb((uv_stream_t*)handle, 0, &buf);
         } else {
           /* Ouch! serious error. */
           handle->flags &= ~UV_HANDLE_READING;
@@ -995,7 +995,7 @@ void uv_process_tcp_read_req(uv_loop_t* loop, uv_tcp_t* handle,
 
           handle->read_cb((uv_stream_t*)handle,
                           uv_translate_sys_error(err),
-                          buf);
+                          &buf);
         }
         break;
       }
diff --git a/src/win/tty.c b/src/win/tty.c
index b3eea839a..60c301480 100644
--- a/src/win/tty.c
+++ b/src/win/tty.c
@@ -349,7 +349,9 @@ static void uv_tty_queue_read_line(uv_loop_t* loop, uv_tty_t* handle) {
 
   handle->alloc_cb((uv_handle_t*) handle, 8192, &handle->read_line_buffer);
   if (handle->read_line_buffer.len == 0) {
-    handle->read_cb(handle, UV_ENOBUFS, handle->read_line_buffer);
+    handle->read_cb((uv_stream_t*) handle,
+                    UV_ENOBUFS,
+                    &handle->read_line_buffer);
     return;
   }
   assert(handle->read_line_buffer.base != NULL);
@@ -486,7 +488,7 @@ void uv_process_tty_read_raw_req(uv_loop_t* loop, uv_tty_t* handle,
       handle->flags &= ~UV_HANDLE_READING;
       handle->read_cb((uv_stream_t*)handle,
                       uv_translate_sys_error(GET_REQ_ERROR(req)),
-                      uv_null_buf_);
+                      &uv_null_buf_);
     }
     goto out;
   }
@@ -497,7 +499,7 @@ void uv_process_tty_read_raw_req(uv_loop_t* loop, uv_tty_t* handle,
     DECREASE_ACTIVE_COUNT(loop, handle);
     handle->read_cb((uv_stream_t*)handle,
                     uv_translate_sys_error(GetLastError()),
-                    uv_null_buf_);
+                    &uv_null_buf_);
     goto out;
   }
 
@@ -518,7 +520,7 @@ void uv_process_tty_read_raw_req(uv_loop_t* loop, uv_tty_t* handle,
         DECREASE_ACTIVE_COUNT(loop, handle);
         handle->read_cb((uv_stream_t*) handle,
                         uv_translate_sys_error(GetLastError()),
-                        buf);
+                        &buf);
         goto out;
       }
       records_left--;
@@ -638,7 +640,7 @@ void uv_process_tty_read_raw_req(uv_loop_t* loop, uv_tty_t* handle,
           DECREASE_ACTIVE_COUNT(loop, handle);
           handle->read_cb((uv_stream_t*) handle,
                           uv_translate_sys_error(GetLastError()),
-                          buf);
+                          &buf);
           goto out;
         }
 
@@ -686,7 +688,7 @@ void uv_process_tty_read_raw_req(uv_loop_t* loop, uv_tty_t* handle,
         if (buf_used == 0) {
           handle->alloc_cb((uv_handle_t*) handle, 1024, &buf);
           if (buf.len == 0) {
-            handle->read_cb((uv_stream_t*) handle, UV_ENOBUFS, buf);
+            handle->read_cb((uv_stream_t*) handle, UV_ENOBUFS, &buf);
             goto out;
           }
           assert(buf.base != NULL);
@@ -696,7 +698,7 @@ void uv_process_tty_read_raw_req(uv_loop_t* loop, uv_tty_t* handle,
 
         /* If the buffer is full, emit it */
         if (buf_used == buf.len) {
-          handle->read_cb((uv_stream_t*) handle, buf_used, buf);
+          handle->read_cb((uv_stream_t*) handle, buf_used, &buf);
           buf = uv_null_buf_;
           buf_used = 0;
         }
@@ -717,7 +719,7 @@ void uv_process_tty_read_raw_req(uv_loop_t* loop, uv_tty_t* handle,
 
   /* Send the buffer back to the user */
   if (buf_used > 0) {
-    handle->read_cb((uv_stream_t*) handle, buf_used, buf);
+    handle->read_cb((uv_stream_t*) handle, buf_used, &buf);
   }
 
  out:
@@ -755,17 +757,17 @@ void uv_process_tty_read_line_req(uv_loop_t* loop, uv_tty_t* handle,
       DECREASE_ACTIVE_COUNT(loop, handle);
       handle->read_cb((uv_stream_t*) handle,
                       uv_translate_sys_error(GET_REQ_ERROR(req)),
-                      buf);
+                      &buf);
     } else {
       /* The read was cancelled, or whatever we don't care */
-      handle->read_cb((uv_stream_t*) handle, 0, buf);
+      handle->read_cb((uv_stream_t*) handle, 0, &buf);
     }
 
   } else {
     /* Read successful */
     /* TODO: read unicode, convert to utf-8 */
     DWORD bytes = req->overlapped.InternalHigh;
-    handle->read_cb((uv_stream_t*) handle, bytes, buf);
+    handle->read_cb((uv_stream_t*) handle, bytes, &buf);
   }
 
   /* Wait for more input events. */
diff --git a/test/benchmark-multi-accept.c b/test/benchmark-multi-accept.c
index 72ca1fa32..91571450b 100644
--- a/test/benchmark-multi-accept.c
+++ b/test/benchmark-multi-accept.c
@@ -85,7 +85,7 @@ static void ipc_close_cb(uv_handle_t* handle);
 static void ipc_connect_cb(uv_connect_t* req, int status);
 static void ipc_read2_cb(uv_pipe_t* ipc_pipe,
                          ssize_t nread,
-                         uv_buf_t buf,
+                         const uv_buf_t* buf,
                          uv_handle_type type);
 static void ipc_alloc_cb(uv_handle_t* handle,
                          size_t suggested_size,
@@ -93,7 +93,7 @@ static void ipc_alloc_cb(uv_handle_t* handle,
 
 static void sv_async_cb(uv_async_t* handle, int status);
 static void sv_connection_cb(uv_stream_t* server_handle, int status);
-static void sv_read_cb(uv_stream_t* handle, ssize_t nread, uv_buf_t buf);
+static void sv_read_cb(uv_stream_t* handle, ssize_t nread, const uv_buf_t* buf);
 static void sv_alloc_cb(uv_handle_t* handle,
                         size_t suggested_size,
                         uv_buf_t* buf);
@@ -173,7 +173,7 @@ static void ipc_alloc_cb(uv_handle_t* handle,
 
 static void ipc_read2_cb(uv_pipe_t* ipc_pipe,
                          ssize_t nread,
-                         uv_buf_t buf,
+                         const uv_buf_t* buf,
                          uv_handle_type type) {
   struct ipc_client_ctx* ctx;
   uv_loop_t* loop;
@@ -311,7 +311,9 @@ static void sv_alloc_cb(uv_handle_t* handle,
 }
 
 
-static void sv_read_cb(uv_stream_t* handle, ssize_t nread, uv_buf_t buf) {
+static void sv_read_cb(uv_stream_t* handle,
+                       ssize_t nread,
+                       const uv_buf_t* buf) {
   ASSERT(nread == UV_EOF);
   uv_close((uv_handle_t*) handle, (uv_close_cb) free);
 }
diff --git a/test/benchmark-ping-pongs.c b/test/benchmark-ping-pongs.c
index daa145386..982e41eb5 100644
--- a/test/benchmark-ping-pongs.c
+++ b/test/benchmark-ping-pongs.c
@@ -69,9 +69,8 @@ static void buf_alloc(uv_handle_t* tcp, size_t size, uv_buf_t* buf) {
 }
 
 
-static void buf_free(uv_buf_t uv_buf_t) {
-  buf_t* ab = (buf_t*) (uv_buf_t.base - sizeof *ab);
-
+static void buf_free(const uv_buf_t* buf) {
+  buf_t* ab = (buf_t*) buf->base - 1;
   ab->next = buf_freelist;
   buf_freelist = ab;
 }
@@ -121,7 +120,9 @@ static void pinger_shutdown_cb(uv_shutdown_t* req, int status) {
 }
 
 
-static void pinger_read_cb(uv_stream_t* tcp, ssize_t nread, uv_buf_t buf) {
+static void pinger_read_cb(uv_stream_t* tcp,
+                           ssize_t nread,
+                           const uv_buf_t* buf) {
   ssize_t i;
   pinger_t* pinger;
 
@@ -130,7 +131,7 @@ static void pinger_read_cb(uv_stream_t* tcp, ssize_t nread, uv_buf_t buf) {
   if (nread < 0) {
     ASSERT(nread == UV_EOF);
 
-    if (buf.base) {
+    if (buf->base) {
       buf_free(buf);
     }
 
@@ -142,7 +143,7 @@ static void pinger_read_cb(uv_stream_t* tcp, ssize_t nread, uv_buf_t buf) {
 
   /* Now we count the pings */
   for (i = 0; i < nread; i++) {
-    ASSERT(buf.base[i] == PING[pinger->state]);
+    ASSERT(buf->base[i] == PING[pinger->state]);
     pinger->state = (pinger->state + 1) % (sizeof(PING) - 1);
     if (pinger->state == 0) {
       pinger->pongs++;
diff --git a/test/benchmark-pound.c b/test/benchmark-pound.c
index 555a5283a..23ee51ef0 100644
--- a/test/benchmark-pound.c
+++ b/test/benchmark-pound.c
@@ -77,7 +77,7 @@ static int conns_failed;
 
 static void alloc_cb(uv_handle_t* handle, size_t suggested_size, uv_buf_t* buf);
 static void connect_cb(uv_connect_t* conn_req, int status);
-static void read_cb(uv_stream_t* stream, ssize_t nread, uv_buf_t buf);
+static void read_cb(uv_stream_t* stream, ssize_t nread, const uv_buf_t* buf);
 static void close_cb(uv_handle_t* handle);
 
 
@@ -135,7 +135,7 @@ static void connect_cb(uv_connect_t* req, int status) {
 }
 
 
-static void read_cb(uv_stream_t* stream, ssize_t nread, uv_buf_t buf) {
+static void read_cb(uv_stream_t* stream, ssize_t nread, const uv_buf_t* buf) {
 
   ASSERT(stream != NULL);
 
diff --git a/test/benchmark-pump.c b/test/benchmark-pump.c
index 1d0a058ad..e08850d8c 100644
--- a/test/benchmark-pump.c
+++ b/test/benchmark-pump.c
@@ -42,7 +42,7 @@ static uv_req_t* req_alloc();
 static void req_free(uv_req_t* uv_req);
 
 static void buf_alloc(uv_handle_t* handle, size_t size, uv_buf_t* buf);
-static void buf_free(uv_buf_t uv_buf_t);
+static void buf_free(const uv_buf_t* buf);
 
 static uv_loop_t* loop;
 
@@ -158,7 +158,7 @@ static void start_stats_collection(void) {
 }
 
 
-static void read_cb(uv_stream_t* stream, ssize_t bytes, uv_buf_t buf) {
+static void read_cb(uv_stream_t* stream, ssize_t bytes, const uv_buf_t* buf) {
   if (nrecv_total == 0) {
     ASSERT(start_time == 0);
     uv_update_time(loop);
@@ -347,11 +347,10 @@ static void buf_alloc(uv_handle_t* handle, size_t size, uv_buf_t* buf) {
 }
 
 
-static void buf_free(uv_buf_t uv_buf_t) {
-  buf_list_t* buf = (buf_list_t*) (uv_buf_t.base - sizeof *buf);
-
-  buf->next = buf_freelist;
-  buf_freelist = buf;
+static void buf_free(const uv_buf_t* buf) {
+  buf_list_t* ab = (buf_list_t*) buf->base - 1;
+  ab->next = buf_freelist;
+  buf_freelist = ab;
 }
 
 
diff --git a/test/benchmark-spawn.c b/test/benchmark-spawn.c
index 683e9b11a..30bc328be 100644
--- a/test/benchmark-spawn.c
+++ b/test/benchmark-spawn.c
@@ -88,7 +88,7 @@ static void pipe_close_cb(uv_handle_t* pipe) {
 }
 
 
-static void on_read(uv_stream_t* pipe, ssize_t nread, uv_buf_t buf) {
+static void on_read(uv_stream_t* pipe, ssize_t nread, const uv_buf_t* buf) {
   if (nread > 0) {
     ASSERT(pipe_open == 1);
     output_used += nread;
diff --git a/test/blackhole-server.c b/test/blackhole-server.c
index 2ff50b6c5..47dcebdf2 100644
--- a/test/blackhole-server.c
+++ b/test/blackhole-server.c
@@ -34,7 +34,7 @@ static uv_tcp_t tcp_server;
 
 static void connection_cb(uv_stream_t* stream, int status);
 static void alloc_cb(uv_handle_t* handle, size_t suggested_size, uv_buf_t* buf);
-static void read_cb(uv_stream_t* stream, ssize_t nread, uv_buf_t buf);
+static void read_cb(uv_stream_t* stream, ssize_t nread, const uv_buf_t* buf);
 static void shutdown_cb(uv_shutdown_t* req, int status);
 static void close_cb(uv_handle_t* handle);
 
@@ -69,7 +69,7 @@ static void alloc_cb(uv_handle_t* handle,
 }
 
 
-static void read_cb(uv_stream_t* stream, ssize_t nread, uv_buf_t buf) {
+static void read_cb(uv_stream_t* stream, ssize_t nread, const uv_buf_t* buf) {
   conn_rec* conn;
   int r;
 
diff --git a/test/dns-server.c b/test/dns-server.c
index ebeb933d5..6bb807e26 100644
--- a/test/dns-server.c
+++ b/test/dns-server.c
@@ -54,7 +54,7 @@ static uv_tcp_t server;
 
 
 static void after_write(uv_write_t* req, int status);
-static void after_read(uv_stream_t*, ssize_t nread, uv_buf_t buf);
+static void after_read(uv_stream_t*, ssize_t nread, const uv_buf_t* buf);
 static void on_close(uv_handle_t* peer);
 static void on_connection(uv_stream_t*, int status);
 
@@ -124,7 +124,9 @@ static void addrsp(write_req_t* wr, char* hdr) {
   wr->buf.len += rsplen;
 }
 
-static void process_req(uv_stream_t* handle, ssize_t nread, uv_buf_t buf) {
+static void process_req(uv_stream_t* handle,
+                        ssize_t nread,
+                        const uv_buf_t* buf) {
   write_req_t* wr;
   dnshandle* dns = (dnshandle*)handle;
   char hdrbuf[DNSREC_LEN];
@@ -144,7 +146,7 @@ static void process_req(uv_stream_t* handle, ssize_t nread, uv_buf_t buf) {
     readbuf_remaining = dns->state.prevbuf_rem;
     usingprev = 1;
   } else {
-    dnsreq = buf.base;
+    dnsreq = buf->base;
     readbuf_remaining = nread;
   }
   hdrstart = dnsreq;
@@ -194,7 +196,7 @@ static void process_req(uv_stream_t* handle, ssize_t nread, uv_buf_t buf) {
     if (usingprev == 1) {
       /* free previous buffer */
       free(dns->state.prevbuf_ptr);
-      dnsreq = buf.base;
+      dnsreq = buf->base;
       readbuf_remaining = nread;
       usingprev = 0;
     } else {
@@ -211,27 +213,29 @@ static void process_req(uv_stream_t* handle, ssize_t nread, uv_buf_t buf) {
 
   if (readbuf_remaining > 0) {
     /* save start of record position, so we can continue on next read */
-    dns->state.prevbuf_ptr = buf.base;
-    dns->state.prevbuf_pos = hdrstart - buf.base;
+    dns->state.prevbuf_ptr = buf->base;
+    dns->state.prevbuf_pos = hdrstart - buf->base;
     dns->state.prevbuf_rem = nread - dns->state.prevbuf_pos;
   } else {
     /* nothing left in this buffer */
     dns->state.prevbuf_ptr = NULL;
     dns->state.prevbuf_pos = 0;
     dns->state.prevbuf_rem = 0;
-    free(buf.base);
+    free(buf->base);
   }
 }
 
-static void after_read(uv_stream_t* handle, ssize_t nread, uv_buf_t buf) {
+static void after_read(uv_stream_t* handle,
+                       ssize_t nread,
+                       const uv_buf_t* buf) {
   uv_shutdown_t* req;
 
   if (nread < 0) {
     /* Error or EOF */
     ASSERT(nread == UV_EOF);
 
-    if (buf.base) {
-      free(buf.base);
+    if (buf->base) {
+      free(buf->base);
     }
 
     req = malloc(sizeof *req);
@@ -242,7 +246,7 @@ static void after_read(uv_stream_t* handle, ssize_t nread, uv_buf_t buf) {
 
   if (nread == 0) {
     /* Everything OK, but nothing read. */
-    free(buf.base);
+    free(buf->base);
     return;
   }
   /* process requests and send responses */
diff --git a/test/echo-server.c b/test/echo-server.c
index 71c116228..4f349a0e7 100644
--- a/test/echo-server.c
+++ b/test/echo-server.c
@@ -39,7 +39,7 @@ static uv_pipe_t pipeServer;
 static uv_handle_t* server;
 
 static void after_write(uv_write_t* req, int status);
-static void after_read(uv_stream_t*, ssize_t nread, uv_buf_t buf);
+static void after_read(uv_stream_t*, ssize_t nread, const uv_buf_t* buf);
 static void on_close(uv_handle_t* peer);
 static void on_server_close(uv_handle_t* handle);
 static void on_connection(uv_stream_t*, int status);
@@ -72,7 +72,9 @@ static void after_shutdown(uv_shutdown_t* req, int status) {
 }
 
 
-static void after_read(uv_stream_t* handle, ssize_t nread, uv_buf_t buf) {
+static void after_read(uv_stream_t* handle,
+                       ssize_t nread,
+                       const uv_buf_t* buf) {
   int i;
   write_req_t *wr;
   uv_shutdown_t* req;
@@ -81,8 +83,8 @@ static void after_read(uv_stream_t* handle, ssize_t nread, uv_buf_t buf) {
     /* Error or EOF */
     ASSERT(nread == UV_EOF);
 
-    if (buf.base) {
-      free(buf.base);
+    if (buf->base) {
+      free(buf->base);
     }
 
     req = (uv_shutdown_t*) malloc(sizeof *req);
@@ -93,7 +95,7 @@ static void after_read(uv_stream_t* handle, ssize_t nread, uv_buf_t buf) {
 
   if (nread == 0) {
     /* Everything OK, but nothing read. */
-    free(buf.base);
+    free(buf->base);
     return;
   }
 
@@ -103,9 +105,9 @@ static void after_read(uv_stream_t* handle, ssize_t nread, uv_buf_t buf) {
    */
   if (!server_closed) {
     for (i = 0; i < nread; i++) {
-      if (buf.base[i] == 'Q') {
-        if (i + 1 < nread && buf.base[i + 1] == 'S') {
-          free(buf.base);
+      if (buf->base[i] == 'Q') {
+        if (i + 1 < nread && buf->base[i + 1] == 'S') {
+          free(buf->base);
           uv_close((uv_handle_t*)handle, on_close);
           return;
         } else {
@@ -118,7 +120,7 @@ static void after_read(uv_stream_t* handle, ssize_t nread, uv_buf_t buf) {
 
   wr = (write_req_t*) malloc(sizeof *wr);
 
-  wr->buf = uv_buf_init(buf.base, nread);
+  wr->buf = uv_buf_init(buf->base, nread);
   if (uv_write(&wr->req, handle, &wr->buf, 1, after_write)) {
     FATAL("uv_write failed");
   }
diff --git a/test/test-callback-stack.c b/test/test-callback-stack.c
index 7e848e805..8ac30f89f 100644
--- a/test/test-callback-stack.c
+++ b/test/test-callback-stack.c
@@ -67,11 +67,11 @@ static void shutdown_cb(uv_shutdown_t* req, int status) {
 }
 
 
-static void read_cb(uv_stream_t* tcp, ssize_t nread, uv_buf_t buf) {
+static void read_cb(uv_stream_t* tcp, ssize_t nread, const uv_buf_t* buf) {
   ASSERT(nested == 0 && "read_cb must be called from a fresh stack");
 
   printf("Read. nread == %d\n", (int)nread);
-  free(buf.base);
+  free(buf->base);
 
   if (nread == 0) {
     return;
diff --git a/test/test-delayed-accept.c b/test/test-delayed-accept.c
index 937b47c2c..15ea093f3 100644
--- a/test/test-delayed-accept.c
+++ b/test/test-delayed-accept.c
@@ -115,11 +115,11 @@ static void start_server(void) {
 }
 
 
-static void read_cb(uv_stream_t* tcp, ssize_t nread, uv_buf_t buf) {
+static void read_cb(uv_stream_t* tcp, ssize_t nread, const uv_buf_t* buf) {
   /* The server will not send anything, it should close gracefully. */
 
-  if (buf.base) {
-    free(buf.base);
+  if (buf->base) {
+    free(buf->base);
   }
 
   if (nread >= 0) {
diff --git a/test/test-getsockname.c b/test/test-getsockname.c
index 0c9b6a60e..e447906bf 100644
--- a/test/test-getsockname.c
+++ b/test/test-getsockname.c
@@ -60,12 +60,14 @@ static void after_shutdown(uv_shutdown_t* req, int status) {
 }
 
 
-static void after_read(uv_stream_t* handle, ssize_t nread, uv_buf_t buf) {
+static void after_read(uv_stream_t* handle,
+                       ssize_t nread,
+                       const uv_buf_t* buf) {
   uv_shutdown_t* req;
   int r;
 
-  if (buf.base) {
-    free(buf.base);
+  if (buf->base) {
+    free(buf->base);
   }
 
   req = (uv_shutdown_t*) malloc(sizeof *req);
diff --git a/test/test-ipc-send-recv.c b/test/test-ipc-send-recv.c
index 36895573d..ab52b0c9e 100644
--- a/test/test-ipc-send-recv.c
+++ b/test/test-ipc-send-recv.c
@@ -62,7 +62,7 @@ static void alloc_cb(uv_handle_t* handle,
 
 static void recv_cb(uv_pipe_t* handle,
                     ssize_t nread,
-                    uv_buf_t buf,
+                    const uv_buf_t* buf,
                     uv_handle_type pending) {
   int r;
 
@@ -164,15 +164,16 @@ static void write2_cb(uv_write_t* req, int status) {
 
 static void read2_cb(uv_pipe_t* handle,
                      ssize_t nread,
-                     uv_buf_t buf,
+                     const uv_buf_t* rdbuf,
                      uv_handle_type pending) {
+  uv_buf_t wrbuf;
   int r;
 
   ASSERT(pending == UV_NAMED_PIPE || pending == UV_TCP);
   ASSERT(handle == &ctx.channel);
   ASSERT(nread >= 0);
 
-  buf = uv_buf_init(".", 1);
+  wrbuf = uv_buf_init(".", 1);
 
   if (pending == UV_NAMED_PIPE)
     r = uv_pipe_init(ctx.channel.loop, &ctx.recv.pipe, 0);
@@ -187,7 +188,8 @@ static void read2_cb(uv_pipe_t* handle,
 
   r = uv_write2(&ctx.write_req,
                 (uv_stream_t*)&ctx.channel,
-                &buf, 1,
+                &wrbuf,
+                1,
                 &ctx.recv.stream,
                 write2_cb);
   ASSERT(r == 0);
diff --git a/test/test-ipc.c b/test/test-ipc.c
index 95e8e7699..88bc1c339 100644
--- a/test/test-ipc.c
+++ b/test/test-ipc.c
@@ -135,20 +135,22 @@ static void make_many_connections(void) {
 }
 
 
-static void on_read(uv_pipe_t* pipe, ssize_t nread, uv_buf_t buf,
-    uv_handle_type pending) {
+static void on_read(uv_pipe_t* pipe,
+                    ssize_t nread,
+                    const uv_buf_t* buf,
+                    uv_handle_type pending) {
   int r;
   uv_buf_t outbuf;
 
   if (nread == 0) {
     /* Everything OK, but nothing read. */
-    free(buf.base);
+    free(buf->base);
     return;
   }
 
   if (nread < 0) {
     if (nread == UV_EOF) {
-      free(buf.base);
+      free(buf->base);
       return;
     }
 
@@ -159,7 +161,7 @@ static void on_read(uv_pipe_t* pipe, ssize_t nread, uv_buf_t buf,
   fprintf(stderr, "got %d bytes\n", (int)nread);
 
   if (!tcp_server_listening) {
-    ASSERT(nread > 0 && buf.base && pending != UV_UNKNOWN_HANDLE);
+    ASSERT(nread > 0 && buf->base && pending != UV_UNKNOWN_HANDLE);
     read2_cb_called++;
 
     /* Accept the pending TCP server, and start listening on it. */
@@ -176,7 +178,7 @@ static void on_read(uv_pipe_t* pipe, ssize_t nread, uv_buf_t buf,
     tcp_server_listening = 1;
 
     /* Make sure that the expected data is correctly multiplexed. */
-    ASSERT(memcmp("hello\n", buf.base, nread) == 0);
+    ASSERT(memcmp("hello\n", buf->base, nread) == 0);
 
     outbuf = uv_buf_init("world\n", 6);
     r = uv_write(&write_req, (uv_stream_t*)pipe, &outbuf, 1, NULL);
@@ -184,14 +186,14 @@ static void on_read(uv_pipe_t* pipe, ssize_t nread, uv_buf_t buf,
 
     /* Create a bunch of connections to get both servers to accept. */
     make_many_connections();
-  } else if (memcmp("accepted_connection\n", buf.base, nread) == 0) {
+  } else if (memcmp("accepted_connection\n", buf->base, nread) == 0) {
     /* Remote server has accepted a connection.  Close the channel. */
     ASSERT(pending == UV_UNKNOWN_HANDLE);
     remote_conn_accepted = 1;
     uv_close((uv_handle_t*)&channel, NULL);
   }
 
-  free(buf.base);
+  free(buf->base);
 }
 
 
@@ -249,11 +251,11 @@ static void on_read_alloc(uv_handle_t* handle,
 }
 
 
-static void on_tcp_read(uv_stream_t* tcp, ssize_t nread, uv_buf_t buf) {
+static void on_tcp_read(uv_stream_t* tcp, ssize_t nread, const uv_buf_t* buf) {
   ASSERT(nread > 0);
-  ASSERT(memcmp("hello again\n", buf.base, nread) == 0);
+  ASSERT(memcmp("hello again\n", buf->base, nread) == 0);
   ASSERT(tcp == (uv_stream_t*)&tcp_connection);
-  free(buf.base);
+  free(buf->base);
 
   tcp_read_cb_called++;
 
@@ -262,20 +264,22 @@ static void on_tcp_read(uv_stream_t* tcp, ssize_t nread, uv_buf_t buf) {
 }
 
 
-static void on_read_connection(uv_pipe_t* pipe, ssize_t nread, uv_buf_t buf,
-    uv_handle_type pending) {
+static void on_read_connection(uv_pipe_t* pipe,
+                               ssize_t nread,
+                               const uv_buf_t* buf,
+                               uv_handle_type pending) {
   int r;
   uv_buf_t outbuf;
 
   if (nread == 0) {
     /* Everything OK, but nothing read. */
-    free(buf.base);
+    free(buf->base);
     return;
   }
 
   if (nread < 0) {
     if (nread == UV_EOF) {
-      free(buf.base);
+      free(buf->base);
       return;
     }
 
@@ -285,7 +289,7 @@ static void on_read_connection(uv_pipe_t* pipe, ssize_t nread, uv_buf_t buf,
 
   fprintf(stderr, "got %d bytes\n", (int)nread);
 
-  ASSERT(nread > 0 && buf.base && pending != UV_UNKNOWN_HANDLE);
+  ASSERT(nread > 0 && buf->base && pending != UV_UNKNOWN_HANDLE);
   read2_cb_called++;
 
   /* Accept the pending TCP connection */
@@ -297,7 +301,7 @@ static void on_read_connection(uv_pipe_t* pipe, ssize_t nread, uv_buf_t buf,
   ASSERT(r == 0);
 
   /* Make sure that the expected data is correctly multiplexed. */
-  ASSERT(memcmp("hello\n", buf.base, nread) == 0);
+  ASSERT(memcmp("hello\n", buf->base, nread) == 0);
 
   /* Write/read to/from the connection */
   outbuf = uv_buf_init("world\n", 6);
@@ -308,7 +312,7 @@ static void on_read_connection(uv_pipe_t* pipe, ssize_t nread, uv_buf_t buf,
   r = uv_read_start((uv_stream_t*)&tcp_connection, on_read_alloc, on_tcp_read);
   ASSERT(r == 0);
 
-  free(buf.base);
+  free(buf->base);
 }
 
 
@@ -430,13 +434,15 @@ static void tcp_connection_write_cb(uv_write_t* req, int status) {
 }
 
 
-static void on_tcp_child_process_read(uv_stream_t* tcp, ssize_t nread, uv_buf_t buf) {
+static void on_tcp_child_process_read(uv_stream_t* tcp,
+                                      ssize_t nread,
+                                      const uv_buf_t* buf) {
   uv_buf_t outbuf;
   int r;
 
   if (nread < 0) {
     if (nread == UV_EOF) {
-      free(buf.base);
+      free(buf->base);
       return;
     }
 
@@ -445,9 +451,9 @@ static void on_tcp_child_process_read(uv_stream_t* tcp, ssize_t nread, uv_buf_t
   }
 
   ASSERT(nread > 0);
-  ASSERT(memcmp("world\n", buf.base, nread) == 0);
+  ASSERT(memcmp("world\n", buf->base, nread) == 0);
   on_pipe_read_called++;
-  free(buf.base);
+  free(buf->base);
 
   /* Write to the socket */
   outbuf = uv_buf_init("hello again\n", 12);
@@ -520,7 +526,9 @@ static void ipc_on_connection_tcp_conn(uv_stream_t* server, int status) {
     (uv_stream_t*)conn, NULL);
   ASSERT(r == 0);
 
-  r = uv_read_start((uv_stream_t*)conn, on_read_alloc, on_tcp_child_process_read);
+  r = uv_read_start((uv_stream_t*) conn,
+                    on_read_alloc,
+                    on_tcp_child_process_read);
   ASSERT(r == 0);
 
   uv_close((uv_handle_t*)conn, close_cb);
diff --git a/test/test-osx-select.c b/test/test-osx-select.c
index 26a867517..e5e1bf8b4 100644
--- a/test/test-osx-select.c
+++ b/test/test-osx-select.c
@@ -37,7 +37,7 @@ static void alloc_cb(uv_handle_t* handle, size_t size, uv_buf_t* buf) {
 }
 
 
-static void read_cb(uv_stream_t* stream, ssize_t nread, uv_buf_t buf) {
+static void read_cb(uv_stream_t* stream, ssize_t nread, const uv_buf_t* buf) {
   fprintf(stdout, "got data %d\n", ++read_count);
 
   if (read_count == 3)
diff --git a/test/test-ping-pong.c b/test/test-ping-pong.c
index ee605e5fc..856fc9454 100644
--- a/test/test-ping-pong.c
+++ b/test/test-ping-pong.c
@@ -86,7 +86,9 @@ static void pinger_write_ping(pinger_t* pinger) {
 }
 
 
-static void pinger_read_cb(uv_stream_t* stream, ssize_t nread, uv_buf_t buf) {
+static void pinger_read_cb(uv_stream_t* stream,
+                           ssize_t nread,
+                           const uv_buf_t* buf) {
   ssize_t i;
   pinger_t* pinger;
 
@@ -96,7 +98,7 @@ static void pinger_read_cb(uv_stream_t* stream, ssize_t nread, uv_buf_t buf) {
     ASSERT(nread == UV_EOF);
 
     puts("got EOF");
-    free(buf.base);
+    free(buf->base);
 
     uv_close((uv_handle_t*)(&pinger->stream.tcp), pinger_on_close);
 
@@ -105,7 +107,7 @@ static void pinger_read_cb(uv_stream_t* stream, ssize_t nread, uv_buf_t buf) {
 
   /* Now we count the pings */
   for (i = 0; i < nread; i++) {
-    ASSERT(buf.base[i] == PING[pinger->state]);
+    ASSERT(buf->base[i] == PING[pinger->state]);
     pinger->state = (pinger->state + 1) % (sizeof(PING) - 1);
 
     if (pinger->state != 0)
@@ -122,7 +124,7 @@ static void pinger_read_cb(uv_stream_t* stream, ssize_t nread, uv_buf_t buf) {
     }
   }
 
-  free(buf.base);
+  free(buf->base);
 }
 
 
diff --git a/test/test-shutdown-eof.c b/test/test-shutdown-eof.c
index 6b9da3723..ed9f3fbe6 100644
--- a/test/test-shutdown-eof.c
+++ b/test/test-shutdown-eof.c
@@ -45,25 +45,25 @@ static void alloc_cb(uv_handle_t* handle, size_t size, uv_buf_t* buf) {
 }
 
 
-static void read_cb(uv_stream_t* t, ssize_t nread, uv_buf_t buf) {
+static void read_cb(uv_stream_t* t, ssize_t nread, const uv_buf_t* buf) {
   ASSERT((uv_tcp_t*)t == &tcp);
 
   if (nread == 0) {
-    free(buf.base);
+    free(buf->base);
     return;
   }
 
   if (!got_q) {
     ASSERT(nread == 1);
     ASSERT(!got_eof);
-    ASSERT(buf.base[0] == 'Q');
-    free(buf.base);
+    ASSERT(buf->base[0] == 'Q');
+    free(buf->base);
     got_q = 1;
     puts("got Q");
   } else {
     ASSERT(nread == UV_EOF);
-    if (buf.base) {
-      free(buf.base);
+    if (buf->base) {
+      free(buf->base);
     }
     got_eof = 1;
     puts("got EOF");
diff --git a/test/test-spawn.c b/test/test-spawn.c
index 16a9ece65..0646dcb88 100644
--- a/test/test-spawn.c
+++ b/test/test-spawn.c
@@ -126,7 +126,7 @@ static void on_alloc(uv_handle_t* handle,
 }
 
 
-static void on_read(uv_stream_t* tcp, ssize_t nread, uv_buf_t buf) {
+static void on_read(uv_stream_t* tcp, ssize_t nread, const uv_buf_t* buf) {
   if (nread > 0) {
     output_used += nread;
   } else if (nread < 0) {
diff --git a/test/test-stdio-over-pipes.c b/test/test-stdio-over-pipes.c
index 38c816c0b..2a8283aca 100644
--- a/test/test-stdio-over-pipes.c
+++ b/test/test-stdio-over-pipes.c
@@ -95,7 +95,7 @@ static void after_write(uv_write_t* req, int status) {
 }
 
 
-static void on_read(uv_stream_t* tcp, ssize_t nread, uv_buf_t rdbuf) {
+static void on_read(uv_stream_t* tcp, ssize_t nread, const uv_buf_t* rdbuf) {
   uv_write_t* req;
   uv_buf_t wrbuf;
   int r;
@@ -164,12 +164,12 @@ static int after_write_called;
 static uv_pipe_t stdin_pipe;
 static uv_pipe_t stdout_pipe;
 
-static void on_pipe_read(uv_stream_t* tcp, ssize_t nread, uv_buf_t buf) {
+static void on_pipe_read(uv_stream_t* tcp, ssize_t nread, const uv_buf_t* buf) {
   ASSERT(nread > 0);
-  ASSERT(memcmp("hello world\n", buf.base, nread) == 0);
+  ASSERT(memcmp("hello world\n", buf->base, nread) == 0);
   on_pipe_read_called++;
 
-  free(buf.base);
+  free(buf->base);
 
   uv_close((uv_handle_t*)&stdin_pipe, close_cb);
   uv_close((uv_handle_t*)&stdout_pipe, close_cb);
@@ -242,8 +242,7 @@ int stdio_over_pipes_helper(void) {
   uv_ref((uv_handle_t*)&stdout_pipe);
   uv_ref((uv_handle_t*)&stdin_pipe);
 
-  r = uv_read_start((uv_stream_t*)&stdin_pipe, on_read_alloc,
-    on_pipe_read);
+  r = uv_read_start((uv_stream_t*)&stdin_pipe, on_read_alloc, on_pipe_read);
   ASSERT(r == 0);
 
   uv_run(loop, UV_RUN_DEFAULT);
diff --git a/test/test-tcp-open.c b/test/test-tcp-open.c
index 7e106134f..89135dfd0 100644
--- a/test/test-tcp-open.c
+++ b/test/test-tcp-open.c
@@ -96,12 +96,12 @@ static void shutdown_cb(uv_shutdown_t* req, int status) {
 }
 
 
-static void read_cb(uv_stream_t* tcp, ssize_t nread, uv_buf_t buf) {
+static void read_cb(uv_stream_t* tcp, ssize_t nread, const uv_buf_t* buf) {
   ASSERT(tcp != NULL);
 
   if (nread >= 0) {
     ASSERT(nread == 4);
-    ASSERT(memcmp("PING", buf.base, nread) == 0);
+    ASSERT(memcmp("PING", buf->base, nread) == 0);
   }
   else {
     ASSERT(nread == UV_EOF);
diff --git a/test/test-tcp-shutdown-after-write.c b/test/test-tcp-shutdown-after-write.c
index 1c4f29bc8..5359d93b1 100644
--- a/test/test-tcp-shutdown-after-write.c
+++ b/test/test-tcp-shutdown-after-write.c
@@ -73,7 +73,7 @@ static void timer_cb(uv_timer_t* handle, int status) {
 }
 
 
-static void read_cb(uv_stream_t* handle, ssize_t nread, uv_buf_t buf) {
+static void read_cb(uv_stream_t* handle, ssize_t nread, const uv_buf_t* buf) {
 }
 
 
diff --git a/test/test-tcp-unexpected-read.c b/test/test-tcp-unexpected-read.c
index 6197f7868..6ae3d4278 100644
--- a/test/test-tcp-unexpected-read.c
+++ b/test/test-tcp-unexpected-read.c
@@ -54,7 +54,7 @@ static void alloc_cb(uv_handle_t* handle,
 }
 
 
-static void read_cb(uv_stream_t* handle, ssize_t nread, uv_buf_t buf) {
+static void read_cb(uv_stream_t* handle, ssize_t nread, const uv_buf_t* buf) {
   ASSERT(0 && "read_cb should not have been called");
 }
 
diff --git a/test/test-tcp-write-to-half-open-connection.c b/test/test-tcp-write-to-half-open-connection.c
index 5546d86ec..0a04f3d1d 100644
--- a/test/test-tcp-write-to-half-open-connection.c
+++ b/test/test-tcp-write-to-half-open-connection.c
@@ -29,7 +29,7 @@
 static void connection_cb(uv_stream_t* server, int status);
 static void connect_cb(uv_connect_t* req, int status);
 static void write_cb(uv_write_t* req, int status);
-static void read_cb(uv_stream_t* stream, ssize_t nread, uv_buf_t buf);
+static void read_cb(uv_stream_t* stream, ssize_t nread, const uv_buf_t* buf);
 static void alloc_cb(uv_handle_t* handle, size_t suggested_size, uv_buf_t* buf);
 
 static uv_tcp_t tcp_server;
@@ -74,7 +74,7 @@ static void alloc_cb(uv_handle_t* handle,
 }
 
 
-static void read_cb(uv_stream_t* stream, ssize_t nread, uv_buf_t buf) {
+static void read_cb(uv_stream_t* stream, ssize_t nread, const uv_buf_t* buf) {
   if (nread < 0) {
     fprintf(stderr, "read_cb error: %s\n", uv_err_name(nread));
     ASSERT(nread == UV_ECONNRESET || nread == UV_EOF);
diff --git a/test/test-tcp-writealot.c b/test/test-tcp-writealot.c
index 8005de919..2517df4b2 100644
--- a/test/test-tcp-writealot.c
+++ b/test/test-tcp-writealot.c
@@ -77,7 +77,7 @@ static void shutdown_cb(uv_shutdown_t* req, int status) {
 }
 
 
-static void read_cb(uv_stream_t* tcp, ssize_t nread, uv_buf_t buf) {
+static void read_cb(uv_stream_t* tcp, ssize_t nread, const uv_buf_t* buf) {
   ASSERT(tcp != NULL);
 
   if (nread >= 0) {
@@ -89,7 +89,7 @@ static void read_cb(uv_stream_t* tcp, ssize_t nread, uv_buf_t buf) {
     uv_close((uv_handle_t*)tcp, close_cb);
   }
 
-  free(buf.base);
+  free(buf->base);
 }