diff --git a/libraries/AP_OSD/AP_OSD_SITL.cpp b/libraries/AP_OSD/AP_OSD_SITL.cpp
index fd03fe754c..c22097776b 100644
--- a/libraries/AP_OSD/AP_OSD_SITL.cpp
+++ b/libraries/AP_OSD/AP_OSD_SITL.cpp
@@ -34,6 +34,8 @@
 #include <unistd.h>
 #include "pthread.h"
 
+#include <AP_Notify/AP_Notify.h>
+
 extern const AP_HAL::HAL &hal;
 
 /*
@@ -128,49 +130,56 @@ void AP_OSD_SITL::flush(void)
 void AP_OSD_SITL::update_thread(void)
 {
     load_font();
-    w = new sf::RenderWindow(sf::VideoMode(video_cols*(char_width+char_spacing)*char_scale,
-                                           video_lines*(char_height+char_spacing)*char_scale),
-                             "OSD");
+    {
+        WITH_SEMAPHORE(AP::notify().sf_window_mutex);
+        w = new sf::RenderWindow(sf::VideoMode(video_cols*(char_width+char_spacing)*char_scale,
+                                               video_lines*(char_height+char_spacing)*char_scale),
+                                 "OSD");
+    }
     if (!w) {
         AP_HAL::panic("Unable to create OSD window");
     }
 
-    while (w->isOpen()) {
-        sf::Event event;
-        while (w->pollEvent(event)) {
-            if (event.type == sf::Event::Closed) {
-                w->close();
-            }
-        }
-        if (counter == last_counter) {
-            usleep(10000);
-            continue;
-        }
-        last_counter = counter;
-
-        uint8_t buffer2[video_lines][video_cols];
+    while (true) {
         {
-            WITH_SEMAPHORE(mutex);
-            memcpy(buffer2, buffer, sizeof(buffer2));
-        }
-        w->clear();
-
-        for (uint8_t y=0; y<video_lines; y++) {
-            for (uint8_t x=0; x<video_cols; x++) {
-                uint16_t px = x * (char_width+char_spacing) * char_scale;
-                uint16_t py = y * (char_height+char_spacing) * char_scale;
-                sf::Sprite s;
-                uint8_t c = buffer2[y][x];
-                s.setTexture(font[c]);
-                s.setPosition(sf::Vector2f(px, py));
-                s.scale(sf::Vector2f(char_scale,char_scale));
-                w->draw(s);
+            WITH_SEMAPHORE(AP::notify().sf_window_mutex);
+            sf::Event event;
+            while (w->pollEvent(event)) {
+                if (event.type == sf::Event::Closed) {
+                    w->close();
+                }
             }
-        }
+            if (!w->isOpen()) {
+                break;
+            }
+            if (counter != last_counter) {
+                last_counter = counter;
 
-        w->display();
-        if (last_font != get_font_num()) {
-            load_font();
+                uint8_t buffer2[video_lines][video_cols];
+                {
+                    WITH_SEMAPHORE(mutex);
+                    memcpy(buffer2, buffer, sizeof(buffer2));
+                }
+                w->clear();
+
+                for (uint8_t y=0; y<video_lines; y++) {
+                    for (uint8_t x=0; x<video_cols; x++) {
+                        uint16_t px = x * (char_width+char_spacing) * char_scale;
+                        uint16_t py = y * (char_height+char_spacing) * char_scale;
+                        sf::Sprite s;
+                        uint8_t c = buffer2[y][x];
+                        s.setTexture(font[c]);
+                        s.setPosition(sf::Vector2f(px, py));
+                        s.scale(sf::Vector2f(char_scale,char_scale));
+                        w->draw(s);
+                    }
+                }
+
+                w->display();
+                if (last_font != get_font_num()) {
+                    load_font();
+                }
+            }
         }
         usleep(10000);
     }