diff --git a/src/context.c b/src/context.c
index f411250..1fa30f5 100644
--- a/src/context.c
+++ b/src/context.c
@@ -423,19 +423,21 @@ static int set_verify(lua_State *L)
 static int set_options(lua_State *L)
 {
   int i;
+  const char *str;
   unsigned long flag = 0L;
   SSL_CTX *ctx = lsec_checkcontext(L, 1);
   int max = lua_gettop(L);
   /* any option? */
   if (max > 1) {
     for (i = 2; i <= max; i++) {
+      str = luaL_checkstring(L, i);
 #if !defined(SSL_OP_NO_COMPRESSION) && (OPENSSL_VERSION_NUMBER >= 0x0090800f) && (OPENSSL_VERSION_NUMBER < 0x1000000fL)
       /* Version 0.9.8 has a different way to disable compression */
-      if (!strcmp(luaL_checkstring(L, i), "no_compression"))
+      if (!strcmp(str, "no_compression"))
         ctx->comp_methods = NULL;
       else
 #endif
-      if (!set_option_flag(luaL_checkstring(L, i), &flag)) {
+      if (!set_option_flag(str, &flag)) {
         lua_pushboolean(L, 0);
         lua_pushstring(L, "invalid option");
         return 2;