diff --git a/src/test/run-pass/float-nan.rs b/src/test/run-pass/float-nan.rs
index 61ef4373a8c..d0ec3d4f994 100644
--- a/src/test/run-pass/float-nan.rs
+++ b/src/test/run-pass/float-nan.rs
@@ -71,4 +71,12 @@ fn main() {
   assert(float::isNaN(0. / 0.));
   assert(float::isNaN(-inf + inf));
   assert(float::isNaN(inf - inf));
+
+  assert(!float::isNaN(-1.));
+  assert(!float::isNaN(0.));
+  assert(!float::isNaN(0.1));
+  assert(!float::isNaN(1.));
+  assert(!float::isNaN(inf));
+  assert(!float::isNaN(-inf));
+  assert(!float::isNaN(1./-inf));
 }