diff --git a/core/math/parser/parser-tests.factor b/core/math/parser/parser-tests.factor
index c16a031690..cee2314d07 100755
--- a/core/math/parser/parser-tests.factor
+++ b/core/math/parser/parser-tests.factor
@@ -101,7 +101,7 @@ unit-test
 
 [ "-1.0/0.0" ] [ -1.0 0.0 / number>string ] unit-test
 
-[ 0.0/0.0 ] [ "0/0." string>number ] unit-test
+[ t ] [ "0/0." string>number fp-nan? ] unit-test
 
 [ 1.0/0.0 ] [ "1/0." string>number ] unit-test