diff --git a/mozilla/js/ref/jsatom.c b/mozilla/js/ref/jsatom.c
index 86ce81db73c..bab3afe6760 100644
--- a/mozilla/js/ref/jsatom.c
+++ b/mozilla/js/ref/jsatom.c
@@ -114,11 +114,11 @@ js_compare_atom_keys(const void *k1, const void *k2)
     if (JSVAL_IS_DOUBLE(v1) && JSVAL_IS_DOUBLE(v2)) {
         double d1 = *JSVAL_TO_DOUBLE(v1);
         double d2 = *JSVAL_TO_DOUBLE(v2);
-#ifdef XP_PC
-	/* XXX MSVC miscompiles such that (NaN == 0) */
 	if (JSDOUBLE_IS_NaN(d1))
 	    return JSDOUBLE_IS_NaN(d2);
-	else if (JSDOUBLE_IS_NaN(d2))
+#ifdef XP_PC
+	/* XXX MSVC miscompiles such that (NaN == 0) */
+	if (JSDOUBLE_IS_NaN(d2))
             return JS_FALSE;
 #endif
 	return d1 == d2;