diff --git a/src-tauri/src/config/runtime.rs b/src-tauri/src/config/runtime.rs
index 892e6be7..c406c7f0 100644
--- a/src-tauri/src/config/runtime.rs
+++ b/src-tauri/src/config/runtime.rs
@@ -26,20 +26,24 @@ impl IRuntime {
                         config.insert(key.into(), value.clone());
                     }
                 });
-            let tun = config.get("tun");
-            let mut tun = tun.map_or(Mapping::new(), |val| {
-                val.as_mapping().cloned().unwrap_or(Mapping::new())
-            });
+
             let patch_tun = patch.get("tun");
-            let patch_tun = patch_tun.map_or(Mapping::new(), |val| {
-                val.as_mapping().cloned().unwrap_or(Mapping::new())
-            });
-            use_keys(&patch_tun).into_iter().for_each(|key| {
-                if let Some(value) = patch_tun.get(&key).to_owned() {
-                    tun.insert(key.into(), value.clone());
-                }
-            });
-            config.insert("tun".into(), Value::from(tun));
+            if patch_tun.is_some() {
+                let tun = config.get("tun");
+                let mut tun = tun.map_or(Mapping::new(), |val| {
+                    val.as_mapping().cloned().unwrap_or(Mapping::new())
+                });
+                let patch_tun = patch_tun.map_or(Mapping::new(), |val| {
+                    val.as_mapping().cloned().unwrap_or(Mapping::new())
+                });
+                use_keys(&patch_tun).into_iter().for_each(|key| {
+                    if let Some(value) = patch_tun.get(&key).to_owned() {
+                        tun.insert(key.into(), value.clone());
+                    }
+                });
+
+                config.insert("tun".into(), Value::from(tun));
+            }
         }
     }
 }