2 files changed, 11 insertions, 10 deletions

diff --git a/lua_cjson.c b/lua_cjson.c
index 1226e71..806a67c 100644
--- a/lua_cjson.c
+++ b/lua_cjson.c
@@ -623,12 +623,17 @@ static void json_append_number(lua_State *l, strbuf_t *json, int index,
     if (cfg->encode_refuse_badnum && (isinf(num) || isnan(num)))
         json_encode_exception(l, cfg, index, "must not be NaN or Inf");
 
-    /* Lowest double printed with %.14g is 21 characters long:
-     * -1.7976931348623e+308
-     *
-     * Use 32 to include the \0, and a few extra just in case..
-     */
-    strbuf_append_fmt(json, 32, cfg->number_fmt, num);
+    if (isnan(num)) {
+        /* Some platforms may print -nan, just hard code it */
+        strbuf_append_mem(json, "nan", 3);
+    } else {
+        /* Lowest double printed with %.14g is 21 characters long:
+         * -1.7976931348623e+308
+         *
+         * Use 32 to include the \0, and a few extra just in case..
+         */
+        strbuf_append_fmt(json, 32, cfg->number_fmt, num);
+    }
 }
 
 static void json_append_object(lua_State *l, json_config_t *cfg,
diff --git a/tests/test.lua b/tests/test.lua
index d80dcf0..02d3760 100755
--- a/tests/test.lua
+++ b/tests/test.lua
@@ -150,10 +150,6 @@ local encode_error_tests = {
         json.refuse_invalid_numbers(false)
         return 'Setting refuse_invalid_numbers(false).'
     end,
-    function ()
-        print('NOTE: receiving "-nan" in the following test is ok..')
-        return
-    end,
     { json.encode, { NaN }, true, { "nan" } },
     { json.encode, { Inf }, true, { "inf" } },
     function ()