diff --git a/gcc/objc/objc.h b/gcc/objc/objc.h
index 85d05852d45..2b74a1b7af4 100644
--- a/gcc/objc/objc.h
+++ b/gcc/objc/objc.h
@@ -35,7 +35,7 @@ extern "C" {
 /*
 ** Definition of the boolean type.  
 */
-typedef char  BOOL;
+typedef unsigned char  BOOL;
 #define YES   (BOOL)1
 #define NO    (BOOL)0