diff --git a/libraries/AP_Notify/Display.cpp b/libraries/AP_Notify/Display.cpp
index 207e990fee..66d1032dfa 100644
--- a/libraries/AP_Notify/Display.cpp
+++ b/libraries/AP_Notify/Display.cpp
@@ -495,7 +495,7 @@ void Display::update_gps(uint8_t r)
             fixname = gpsfixname[0];
             break;
     }
-    snprintf(msg, DISPLAY_MESSAGE_SIZE, "GPS:%-5s Sats:%2u", fixname, AP_Notify::flags.gps_num_sats) ;
+    snprintf(msg, DISPLAY_MESSAGE_SIZE, "GPS:%-5s Sats:%2u", fixname, (unsigned)AP_Notify::flags.gps_num_sats) ;
     draw_text(COLUMN(0), ROW(r), msg);
 }