diff --git a/src/win/core.c b/src/win/core.c
index ca566c03..497fa883 100644
--- a/src/win/core.c
+++ b/src/win/core.c
@@ -269,11 +269,8 @@ int uv_run(uv_loop_t *loop, uv_run_mode mode) {
   if (!uv__loop_alive(loop))
     return 0;
 
-  do {
-    if (loop->stop_flag) {
-      loop->stop_flag = 0;
-      return uv__loop_alive(loop);
-    }
+  r = uv__loop_alive(loop);
+  while (r != 0 && loop->stop_flag == 0) {
     uv_update_time(loop);
     uv_process_timers(loop);
 
@@ -298,7 +295,15 @@ int uv_run(uv_loop_t *loop, uv_run_mode mode) {
 
     uv_check_invoke(loop);
     r = uv__loop_alive(loop);
-  } while (r && !(mode & (UV_RUN_ONCE | UV_RUN_NOWAIT)));
+    if (mode & (UV_RUN_ONCE | UV_RUN_NOWAIT))
+      break;
+  }
+
+  /* The if statement lets the compiler compile it to a conditional store.
+   * Avoids dirtying a cache line.
+   */
+  if (loop->stop_flag != 0)
+    loop->stop_flag = 0;
 
   return r;
 }
diff --git a/test/test-loop-stop.c b/test/test-loop-stop.c
index 75ff9153..db52a094 100644
--- a/test/test-loop-stop.c
+++ b/test/test-loop-stop.c
@@ -22,11 +22,22 @@
 #include "uv.h"
 #include "task.h"
 
+static uv_prepare_t prepare_handle;
 static uv_timer_t timer_handle;
+static int prepare_called = 0;
 static int timer_called = 0;
 static int num_ticks = 10;
 
 
+static void prepare_cb(uv_prepare_t* handle, int status) {
+  ASSERT(handle == &prepare_handle);
+  ASSERT(status == 0);
+  prepare_called++;
+  if (prepare_called == num_ticks)
+    uv_prepare_stop(handle);
+}
+
+
 static void timer_cb(uv_timer_t* handle, int status) {
   ASSERT(handle == &timer_handle);
   ASSERT(status == 0);
@@ -40,6 +51,8 @@ static void timer_cb(uv_timer_t* handle, int status) {
 
 TEST_IMPL(loop_stop) {
   int r;
+  uv_prepare_init(uv_default_loop(), &prepare_handle);
+  uv_prepare_start(&prepare_handle, prepare_cb);
   uv_timer_init(uv_default_loop(), &timer_handle);
   uv_timer_start(&timer_handle, timer_cb, 100, 100);
 
@@ -47,9 +60,14 @@ TEST_IMPL(loop_stop) {
   ASSERT(r != 0);
   ASSERT(timer_called == 1);
 
+  r = uv_run(uv_default_loop(), UV_RUN_NOWAIT);
+  ASSERT(r != 0);
+  ASSERT(prepare_called == 3);
+
   r = uv_run(uv_default_loop(), UV_RUN_DEFAULT);
   ASSERT(r == 0);
   ASSERT(timer_called == 10);
+  ASSERT(prepare_called == 10);
 
   return 0;
 }