diff --git a/src/hb-ot-shape-complex-use.cc b/src/hb-ot-shape-complex-use.cc
index cc2a9d4d8..d7138c8c2 100644
--- a/src/hb-ot-shape-complex-use.cc
+++ b/src/hb-ot-shape-complex-use.cc
@@ -572,7 +572,7 @@ compose_use (const hb_ot_shape_normalize_context_t *c,
   if (HB_UNICODE_GENERAL_CATEGORY_IS_MARK (c->unicode->general_category (a)))
     return false;
 
-  return c->unicode->compose (a, b, ab) != 0;
+  return (bool)c->unicode->compose (a, b, ab);
 }