diff --git a/src/libguac/display-render-thread.c b/src/libguac/display-render-thread.c
index 13f70369..121c3d23 100644
--- a/src/libguac/display-render-thread.c
+++ b/src/libguac/display-render-thread.c
@@ -141,9 +141,10 @@ static void* guac_display_render_loop(void* data) {
             }
 
             /* Use explicit frame boundaries whenever available */
-            if (render_thread->state.value & GUAC_DISPLAY_RENDER_THREAD_STATE_FRAME_READY) {
+            if (guac_flag_timedwait_and_lock(&render_thread->state,
+                        GUAC_DISPLAY_RENDER_THREAD_STATE_FRAME_READY, 0)) {
 
-                rendered_frames = render_thread->frames;
+                rendered_frames += render_thread->frames;
                 render_thread->frames = 0;
 
                 guac_flag_clear(&render_thread->state,
diff --git a/src/libguac/flag.c b/src/libguac/flag.c
index 5f44ac31..39afb5a0 100644
--- a/src/libguac/flag.c
+++ b/src/libguac/flag.c
@@ -139,6 +139,17 @@ int guac_flag_timedwait_and_lock(guac_flag* event_flag,
 
     guac_flag_lock(event_flag);
 
+    /* Short path: skip wait completely when possible */
+    if (!msec_timeout) {
+
+        int retval = event_flag->value & flags;
+        if (!retval)
+            guac_flag_unlock(event_flag);
+
+        return retval;
+
+    }
+
     struct timespec ts_timeout;
     clock_gettime(CLOCK_MONOTONIC, &ts_timeout);