diff --git a/docs/README.md b/docs/README.md
index 6390e5ec..808a4966 100644
--- a/docs/README.md
+++ b/docs/README.md
@@ -657,7 +657,7 @@ Usage example: see [examples/multi-threaded](https://github.com/cesanta/mongoose
 ### mg\_mgr\_wakeup()
 
 ```c
-void mg_mgr_wakeup(struct mg_connection *pipe, const void *buf, size_len len);
+bool mg_mgr_wakeup(struct mg_connection *pipe, const void *buf, size_len len);
 ```
 
 Wake up an event manager that sleeps in `mg_mgr_poll()` call. This function
@@ -673,7 +673,7 @@ Parameters:
 - `buf` - a data to send to the pipe connection. Use `""` if there is no data 
 - `len` - a data length
 
-Return value: None
+Return value: `true` if data has been sent, `false` otherwise
 
 Usage example: see [examples/multi-threaded](https://github.com/cesanta/mongoose/tree/master/examples/multi-threaded).
 
diff --git a/mongoose.c b/mongoose.c
index e584d019..03a0bf5c 100644
--- a/mongoose.c
+++ b/mongoose.c
@@ -3542,11 +3542,10 @@ static bool mg_socketpair(SOCKET sp[2], union usa usa[2]) {
   return result;
 }
 
-void mg_mgr_wakeup(struct mg_connection *c, const void *buf, size_t len) {
+bool mg_mgr_wakeup(struct mg_connection *c, const void *buf, size_t len) {
   if (buf == NULL || len == 0) buf = (void *) "", len = 1;
-  if ((size_t) send((SOCKET) (size_t) c->pfn_data, (const char *) buf, len,
-                    MSG_NONBLOCKING) != len)
-    (void) 0;
+  return (size_t) send((SOCKET) (size_t) c->pfn_data, (const char *) buf, len,
+                       MSG_NONBLOCKING) == len;
 }
 
 static void pf1(struct mg_connection *c, int ev, void *ev_data, void *fn_data) {
diff --git a/mongoose.h b/mongoose.h
index ef18b6df..388ca955 100644
--- a/mongoose.h
+++ b/mongoose.h
@@ -953,7 +953,7 @@ bool mg_aton(struct mg_str str, struct mg_addr *addr);
 char *mg_ntoa(const struct mg_addr *addr, char *buf, size_t len);
 
 struct mg_connection *mg_mkpipe(struct mg_mgr *, mg_event_handler_t, void *);
-void mg_mgr_wakeup(struct mg_connection *pipe, const void *buf, size_t len);
+bool mg_mgr_wakeup(struct mg_connection *pipe, const void *buf, size_t len);
 
 // These functions are used to integrate with custom network stacks
 struct mg_connection *mg_alloc_conn(struct mg_mgr *);
diff --git a/src/net.h b/src/net.h
index aa895d6a..22f7b118 100644
--- a/src/net.h
+++ b/src/net.h
@@ -77,7 +77,7 @@ bool mg_aton(struct mg_str str, struct mg_addr *addr);
 char *mg_ntoa(const struct mg_addr *addr, char *buf, size_t len);
 
 struct mg_connection *mg_mkpipe(struct mg_mgr *, mg_event_handler_t, void *);
-void mg_mgr_wakeup(struct mg_connection *pipe, const void *buf, size_t len);
+bool mg_mgr_wakeup(struct mg_connection *pipe, const void *buf, size_t len);
 
 // These functions are used to integrate with custom network stacks
 struct mg_connection *mg_alloc_conn(struct mg_mgr *);
diff --git a/src/sock.c b/src/sock.c
index e0453c24..ce774fb9 100644
--- a/src/sock.c
+++ b/src/sock.c
@@ -413,11 +413,10 @@ static bool mg_socketpair(SOCKET sp[2], union usa usa[2]) {
   return result;
 }
 
-void mg_mgr_wakeup(struct mg_connection *c, const void *buf, size_t len) {
+bool mg_mgr_wakeup(struct mg_connection *c, const void *buf, size_t len) {
   if (buf == NULL || len == 0) buf = (void *) "", len = 1;
-  if ((size_t) send((SOCKET) (size_t) c->pfn_data, (const char *) buf, len,
-                    MSG_NONBLOCKING) != len)
-    (void) 0;
+  return (size_t) send((SOCKET) (size_t) c->pfn_data, (const char *) buf, len,
+                       MSG_NONBLOCKING) == len;
 }
 
 static void pf1(struct mg_connection *c, int ev, void *ev_data, void *fn_data) {