diff --git a/freeglut/freeglut/src/freeglut_font.c b/freeglut/freeglut/src/freeglut_font.c
index c1e1db6..596a491 100644
--- a/freeglut/freeglut/src/freeglut_font.c
+++ b/freeglut/freeglut/src/freeglut_font.c
@@ -121,7 +121,7 @@ void FGAPIENTRY glutBitmapCharacter( void* fontID, int character )
   /*
    * Make sure the character we want to output is valid
    */
-  freeglut_return_if_fail( character >= 0 && character < 256 );
+  freeglut_return_if_fail( character >= 1 && character < 256 );
 
   /*
    * Then find the character we want to draw