diff --git a/src/hb-private.h b/src/hb-private.h
index 8a323decf..866ee59c0 100644
--- a/src/hb-private.h
+++ b/src/hb-private.h
@@ -85,15 +85,7 @@
 
 
 #if defined(__GNUC__) && (__GNUC__ > 2) && defined(__OPTIMIZE__)
-#define _HB_BOOLEAN_EXPR(expr) \
-  __extension__ ({ \
-     int _hb_boolean_var_; \
-     if (expr) \
-	_hb_boolean_var_ = 1; \
-     else \
-	_hb_boolean_var_ = 0; \
-     _hb_boolean_var_; \
-  })
+#define _HB_BOOLEAN_EXPR(expr) ((expr) ? 1 : 0)
 #define likely(expr) (__builtin_expect (_HB_BOOLEAN_EXPR(expr), 1))
 #define unlikely(expr) (__builtin_expect (_HB_BOOLEAN_EXPR(expr), 0))
 #else