diff --git a/src/sync/rwmutex.go b/src/sync/rwmutex.go
index aafd6a7010..dc0faf6a60 100644
--- a/src/sync/rwmutex.go
+++ b/src/sync/rwmutex.go
@@ -66,21 +66,26 @@ func (rw *RWMutex) RUnlock() {
 		race.Disable()
 	}
 	if r := atomic.AddInt32(&rw.readerCount, -1); r < 0 {
-		if r+1 == 0 || r+1 == -rwmutexMaxReaders {
-			race.Enable()
-			throw("sync: RUnlock of unlocked RWMutex")
-		}
-		// A writer is pending.
-		if atomic.AddInt32(&rw.readerWait, -1) == 0 {
-			// The last reader unblocks the writer.
-			runtime_Semrelease(&rw.writerSem, false, 0)
-		}
+		// Outlined slow-path to allow the fast-path to be inlined
+		rw.rUnlockSlow(r)
 	}
 	if race.Enabled {
 		race.Enable()
 	}
 }
 
+func (rw *RWMutex) rUnlockSlow(r int32) {
+	if r+1 == 0 || r+1 == -rwmutexMaxReaders {
+		race.Enable()
+		throw("sync: RUnlock of unlocked RWMutex")
+	}
+	// A writer is pending.
+	if atomic.AddInt32(&rw.readerWait, -1) == 0 {
+		// The last reader unblocks the writer.
+		runtime_Semrelease(&rw.writerSem, false, 1)
+	}
+}
+
 // Lock locks rw for writing.
 // If the lock is already locked for reading or writing,
 // Lock blocks until the lock is available.
diff --git a/test/inline_sync.go b/test/inline_sync.go
index 3473b92b4a..46ee4c62ed 100644
--- a/test/inline_sync.go
+++ b/test/inline_sync.go
@@ -38,3 +38,16 @@ func small7() { // ERROR "can inline small7"
         // the Do fast path should be inlined
         once.Do(small5) // ERROR "inlining call to sync\.\(\*Once\)\.Do" "&sync\.o\.done escapes to heap"
 }
+
+var rwmutex *sync.RWMutex
+
+func small8() { // ERROR "can inline small8"
+        // the RUnlock fast path should be inlined
+        rwmutex.RUnlock() // ERROR "inlining call to sync\.\(\*RWMutex\)\.RUnlock" "&sync\.rw\.readerCount escapes to heap"
+}
+
+func small9() { // ERROR "can inline small9"
+        // the RLock fast path should be inlined
+        rwmutex.RLock() // ERROR "inlining call to sync\.\(\*RWMutex\)\.RLock" "&sync\.rw\.readerCount escapes to heap" "&sync\.rw\.readerSem escapes to heap"
+}
+