diff --git a/include/uv.h b/include/uv.h
index ba8098649..ef2f840d7 100644
--- a/include/uv.h
+++ b/include/uv.h
@@ -429,8 +429,8 @@ typedef void (*uv_getaddrinfo_cb)(uv_getaddrinfo_t* req,
                                   struct addrinfo* res);
 typedef void (*uv_getnameinfo_cb)(uv_getnameinfo_t* req,
                                   int status,
-                                  char* hostname,
-                                  char* service);
+                                  const char* hostname,
+                                  const char* service);
 
 typedef struct {
   long tv_sec;
diff --git a/test/test-getnameinfo.c b/test/test-getnameinfo.c
index 707fce014..1ea0f3a43 100644
--- a/test/test-getnameinfo.c
+++ b/test/test-getnameinfo.c
@@ -36,8 +36,8 @@ static uv_getnameinfo_t req;
 
 static void getnameinfo_req(uv_getnameinfo_t* handle,
                             int status,
-                            char* hostname,
-                            char* service) {
+                            const char* hostname,
+                            const char* service) {
   ASSERT(handle != NULL);
   ASSERT(status == 0);
   ASSERT(hostname != NULL);
diff --git a/test/test-threadpool-cancel.c b/test/test-threadpool-cancel.c
index 0c8fd1465..d852e488b 100644
--- a/test/test-threadpool-cancel.c
+++ b/test/test-threadpool-cancel.c
@@ -129,8 +129,8 @@ static void getaddrinfo_cb(uv_getaddrinfo_t* req,
 
 static void getnameinfo_cb(uv_getnameinfo_t* handle,
                            int status,
-                           char* hostname,
-                           char* service) {
+                           const char* hostname,
+                           const char* service) {
   ASSERT(status == UV_EAI_CANCELED);
   ASSERT(hostname == NULL);
   ASSERT(service == NULL);