diff --git a/src/timer/mint/SDL_systimer.c b/src/timer/mint/SDL_systimer.c
index 8c87b9fb5..7de57c0a2 100644
--- a/src/timer/mint/SDL_systimer.c
+++ b/src/timer/mint/SDL_systimer.c
@@ -53,7 +53,7 @@ void SDL_MintAudio_CheckFpu(void);
 
 /* The first ticks value of the application */
 static Uint32 start;
-static SDL_bool supervisor;
+static volatile SDL_bool supervisor;
 static int mint_present;        /* can we use Syield() ? */
 
 void