diff --git a/src/android/com/unprompted/tildefriends/MainActivity.java b/src/android/com/unprompted/tildefriends/MainActivity.java
index bda9dc73..e7eac61c 100644
--- a/src/android/com/unprompted/tildefriends/MainActivity.java
+++ b/src/android/com/unprompted/tildefriends/MainActivity.java
@@ -105,10 +105,13 @@ public class MainActivity extends Activity {
 						for (WatchEvent event : key.pollEvents()) {
 							if (event.context().toString().equals("port.txt")) {
 								Log.w("tildefriends", "Observed file write: " + event.context().toString());
-								base_url = "http://127.0.0.1:" + String.valueOf(read_port(port_file_path)) + "/";
-								activity.runOnUiThread(() -> {
-									web_view.loadUrl(base_url);
-								});
+								int port = read_port(port_file_path);
+								if (port >= 0) {
+									base_url = "http://127.0.0.1:" + String.valueOf(port) + "/";
+									activity.runOnUiThread(() -> {
+										web_view.loadUrl(base_url);
+									});
+								}
 								break;
 							}
 						}