diff --git a/lib/js/runtime.sx b/lib/js/runtime.sx
index 48a647d7..45b89225 100644
--- a/lib/js/runtime.sx
+++ b/lib/js/runtime.sx
@@ -1098,7 +1098,15 @@
         (+ i 1)
         (str acc (js-to-string (nth parts i)))))))
 
-(define js-number-to-string (fn (n) (str n)))
+(define
+  js-number-to-string
+  (fn
+    (n)
+    (cond
+      ((js-number-is-nan n) "NaN")
+      ((= n (js-infinity-value)) "Infinity")
+      ((= n (- 0 (js-infinity-value))) "-Infinity")
+      (else (str n)))))
 
 (define
   js-add