diff --git a/tool/net/lcrypto.c b/tool/net/lcrypto.c
index dc72c8bed..1761bdd20 100644
--- a/tool/net/lcrypto.c
+++ b/tool/net/lcrypto.c
@@ -1110,7 +1110,7 @@ static int LuaCryptoDecrypt(lua_State *L) {
 }
 
 static int LuaCryptoGenerateKeyPair(lua_State *L) {
-    const char *key_type = luaL_checkstring(L, 1); // Key type (e.g., "rsa", "ecdsa")
+    const char *key_type = luaL_optstring(L, 1, "rsa"); // Key type (e.g., "rsa", "ecdsa")
     lua_remove(L, 1); // Remove the first argument (key type or cipher type) before dispatching
 
     if (strcasecmp(key_type, "rsa") == 0) {