diff --git a/freeglut/freeglut/src/freeglut_init.c b/freeglut/freeglut/src/freeglut_init.c
index 0289ddd..c9e85c5 100644
--- a/freeglut/freeglut/src/freeglut_init.c
+++ b/freeglut/freeglut/src/freeglut_init.c
@@ -519,9 +519,13 @@ void FGAPIENTRY glutInit( int* pargc, char** argv )
         const char *fps = getenv( "GLUT_FPS" );
         if( fps )
         {
-            sscanf( fps, "%d", &fgState.FPSInterval );
-            if( fgState.FPSInterval <= 0 )
-                fgState.FPSInterval = 5000;  /* 5000 milliseconds */
+            int interval;
+            sscanf( fps, "%d", &interval );
+            
+            if( interval <= 0 )
+                fgState.FPSInterval = 5000;  /* 5000 millisecond default */
+            else
+                fgState.FPSInterval = interval;
         }
     }