diff --git a/app/src/main/java/dev/kaizen/app/chat/ChatScreen.kt b/app/src/main/java/dev/kaizen/app/chat/ChatScreen.kt
index e7e3032..13fb9f7 100644
--- a/app/src/main/java/dev/kaizen/app/chat/ChatScreen.kt
+++ b/app/src/main/java/dev/kaizen/app/chat/ChatScreen.kt
@@ -1359,7 +1359,7 @@ fun ChatScreen(
                                 isRecording = isRecording,
                                 recordingAmplitude = recordingAmplitude,
                                 onMicClick = { toggleRecording() },
-                                onCallClick = if (liveAvailable) {{ startLiveCall() }} else {{ /* PTT TODO */ }},
+                                onCallClick = if (liveAvailable) {{ startLiveCall() }} else {{ Toast.makeText(context, context.getString(R.string.chat_call_unavailable), Toast.LENGTH_SHORT).show() }},
                                 pendingFiles = pendingFiles,
                                 onAddClick = { showAttachMenu = !showAttachMenu },
                                 onRemoveFile = { id -> pendingFiles.removeAll { it.id == id } },
diff --git a/app/src/main/res/values-en/strings.xml b/app/src/main/res/values-en/strings.xml
index 4ead4bd..9e66cf6 100644
--- a/app/src/main/res/values-en/strings.xml
+++ b/app/src/main/res/values-en/strings.xml
@@ -15,6 +15,7 @@
     <string name="chat_search">Search…</string>
     <string name="chat_attachment">Attachment</string>
     <string name="chat_call">Call</string>
+    <string name="chat_call_unavailable">Live Call unavailable — no live model in Vertex region</string>
     <string name="chat_remove">Remove</string>
     <string name="chat_error">Error</string>
     <string name="chat_open_menu">Open menu</string>
diff --git a/app/src/main/res/values/strings.xml b/app/src/main/res/values/strings.xml
index 43fecf6..8fd3fff 100644
--- a/app/src/main/res/values/strings.xml
+++ b/app/src/main/res/values/strings.xml
@@ -17,6 +17,7 @@
     <string name="chat_search">Suchen…</string>
     <string name="chat_attachment">Anhang</string>
     <string name="chat_call">Anruf</string>
+    <string name="chat_call_unavailable">Live Call nicht verfügbar — kein Live-Modell in der Vertex-Region</string>
     <string name="chat_remove">Entfernen</string>
     <string name="chat_error">Fehler</string>
     <string name="chat_open_menu">Menü öffnen</string>