diff --git a/src/vm/wren_core.c b/src/vm/wren_core.c
index 4f893620..6511b17e 100644
--- a/src/vm/wren_core.c
+++ b/src/vm/wren_core.c
@@ -777,8 +777,8 @@ DEF_PRIMITIVE(num_pow)
 
 DEF_PRIMITIVE(num_fraction)
 {
-  double dummy;
-  RETURN_NUM(modf(AS_NUM(args[0]) , &dummy));
+  double unused;
+  RETURN_NUM(modf(AS_NUM(args[0]) , &unused));
 }
 
 DEF_PRIMITIVE(num_isInfinity)