diff --git a/dmd/expression.c b/dmd/expression.c
index 67b90e60..d21335f7 100644
--- a/dmd/expression.c
+++ b/dmd/expression.c
@@ -1512,7 +1512,8 @@ complex_t IntegerExp::toComplex()
 
 int IntegerExp::isBool(int result)
 {
-    return result ? value != 0 : value == 0;
+    int r = toInteger() != 0;
+    return result ? r : !r;
 }
 
 Expression *IntegerExp::semantic(Scope *sc)