diff --git a/app/src/main/java/me/datenknoten/tueroeffner/MainActivity.java b/app/src/main/java/me/datenknoten/tueroeffner/MainActivity.java
index e1b82e2..b931bc5 100644
--- a/app/src/main/java/me/datenknoten/tueroeffner/MainActivity.java
+++ b/app/src/main/java/me/datenknoten/tueroeffner/MainActivity.java
@@ -216,4 +216,13 @@ public class MainActivity extends ActionBarActivity {
             Toast.makeText(v.getContext(), "Konnte Befehl „Tür öffnen“ nicht ausführen.", Toast.LENGTH_SHORT).show();
         }
     }
+
+    public void buttonLockInnerDoor(View v) {
+        try {
+            new CommandExecuter(getDoorKey()).doInBackground("indoor_lock");
+            Toast.makeText(v.getContext(), getString(R.string.door_open), Toast.LENGTH_SHORT).show();
+        } catch (Exception e) {
+            Toast.makeText(v.getContext(), "Konnte Befehl „Tür schließen“ nicht ausführen.", Toast.LENGTH_SHORT).show();
+        }
+    }
 }
diff --git a/app/src/main/res/layout/fragment_main.xml b/app/src/main/res/layout/fragment_main.xml
index 5fce1ab..a8ad2a0 100644
--- a/app/src/main/res/layout/fragment_main.xml
+++ b/app/src/main/res/layout/fragment_main.xml
@@ -64,6 +64,14 @@
             android:text="@string/button_inner_door_open"
             android:enabled="false"
             android:onClick="buttonUnlockInnerDoor" />
+
+        <Button
+            android:layout_width="wrap_content"
+            android:layout_height="wrap_content"
+            android:text="@string/door_lock"
+            android:id="@+id/button"
+            android:enabled="false"
+            android:onClick="buttonLockInnerDoor" />
     </LinearLayout>
 
 </LinearLayout>
diff --git a/app/src/main/res/values/strings.xml b/app/src/main/res/values/strings.xml
index 4ee4baa..8836ea5 100644
--- a/app/src/main/res/values/strings.xml
+++ b/app/src/main/res/values/strings.xml
@@ -14,5 +14,6 @@
     <string name="buzzer_success">Buzzer betätigt</string>
     <string name="door_unlock">Tür entsperrt</string>
     <string name="door_open">Tür geöffnet</string>
+    <string name="door_lock">Schließen</string>
 
 </resources>