diff --git a/tools/server/server-models.cpp b/tools/server/server-models.cpp
index 7f62dc4edb..3a5bd2b215 100644
--- a/tools/server/server-models.cpp
+++ b/tools/server/server-models.cpp
@@ -324,6 +324,18 @@ void server_models::unload_lru() {
     }
 }
 
+static void add_or_replace_arg(std::vector<std::string> & args, const std::string & key, const std::string & value) {
+    for (size_t i = 0; i < args.size(); i++) {
+        if (args[i] == key && i + 1 < args.size()) {
+            args[i + 1] = value;
+            return;
+        }
+    }
+    // not found, append
+    args.push_back(key);
+    args.push_back(value);
+}
+
 void server_models::load(const std::string & name, bool auto_load) {
     if (!has_model(name)) {
         throw std::runtime_error("model name=" + name + " is not found");
@@ -356,33 +368,23 @@ void server_models::load(const std::string & name, bool auto_load) {
 
         std::vector<std::string> child_args;
         if (auto_load && !meta.args.empty()) {
-            child_args = meta.args; // reuse previous args
-            // update port arg
-            for (size_t i = 0; i < child_args.size(); i++) {
-                if (child_args[i] == "--port" && i + 1 < child_args.size()) {
-                    child_args[i + 1] = std::to_string(inst.meta.port);
-                    break;
-                }
-            }
+            child_args = meta.args; // copy previous args
         } else {
             child_args = base_args; // copy
             if (inst.meta.in_cache) {
-                child_args.push_back("-hf");
-                child_args.push_back(inst.meta.name);
+                add_or_replace_arg(child_args, "-hf", inst.meta.name);
             } else {
-                child_args.push_back("-m");
-                child_args.push_back(inst.meta.path);
+                add_or_replace_arg(child_args, "-m", inst.meta.path);
                 if (!inst.meta.path_mmproj.empty()) {
-                    child_args.push_back("--mmproj");
-                    child_args.push_back(inst.meta.path_mmproj);
+                    add_or_replace_arg(child_args, "--mmproj", inst.meta.path_mmproj);
                 }
             }
-            child_args.push_back("--alias");
-            child_args.push_back(inst.meta.name);
-            child_args.push_back("--port");
-            child_args.push_back(std::to_string(inst.meta.port));
         }
 
+        // set model args
+        add_or_replace_arg(child_args, "--port", std::to_string(inst.meta.port));
+        add_or_replace_arg(child_args, "--alias", inst.meta.name);
+
         std::vector<std::string> child_env = base_env; // copy
         child_env.push_back("LLAMA_SERVER_ROUTER_PORT=" + std::to_string(base_params.port));