diff --git a/src/testLuaArch.c b/src/testLuaArch.c
index 8f40d74..78bb0f2 100644
--- a/src/testLuaArch.c
+++ b/src/testLuaArch.c
@@ -3,13 +3,14 @@
 #include <lauxlib.h>
 #include <assert.h>
 #include <string.h>
-#include <math.h>
 #include "neonucleus.h"
 
 char *testLuaSandbox = NULL;
 
 #if LUA_VERSION_NUM == 502
 
+#include <math.h>
+
 // monkey patching
 
 bool lua_isinteger(lua_State *L, int i) {
@@ -505,7 +506,7 @@ int testLuaArch_unicode_sub(lua_State *L) {
     }
 
     char *sub = nn_unicode_char(points + start - 1, stop - start + 1);
-    char *res = testLuaArch_pushstring(L, sub);
+    const char *res = testLuaArch_pushstring(L, sub);
     nn_free(sub);
     nn_free(points);
     if (!res) {
@@ -531,7 +532,7 @@ int testLuaArch_unicode_char(lua_State *L) {
         codepoints[i] = lua_tointeger(L, idx);
     }
     char *s = nn_unicode_char(codepoints, argc);
-    char *res = testLuaArch_pushstring(L, s);
+    const char *res = testLuaArch_pushstring(L, s);
     nn_free(s);
     nn_free(codepoints);
     if (!res) {