diff --git a/lang/cem/cemcom.ansi/type.c b/lang/cem/cemcom.ansi/type.c
index 8d8cef68e..208166163 100644
--- a/lang/cem/cemcom.ansi/type.c
+++ b/lang/cem/cemcom.ansi/type.c
@@ -280,7 +280,7 @@ standard_type(fund, sgn, algn, sz)
 {
 	register struct type *tp = create_type(fund);
 
-	tp->tp_unsigned = sgn;
+	tp->tp_unsigned = sgn != 0;
 	tp->tp_align = algn;
 	tp->tp_size = sz;