diff --git a/app/routers/settings.py b/app/routers/settings.py
index 6456104..d54e1b5 100644
--- a/app/routers/settings.py
+++ b/app/routers/settings.py
@@ -475,10 +475,15 @@ async def toggle_tracked_telemetry_contact(
             ),
         )
 
-    # Validate contact exists
+    # Validate contact exists and is not a repeater (repeaters use tracked_telemetry_repeaters)
     contact = await ContactRepository.get_by_key(key)
     if not contact:
         raise HTTPException(status_code=404, detail="Contact not found")
+    if contact.type == CONTACT_TYPE_REPEATER:
+        raise HTTPException(
+            status_code=400,
+            detail="Repeaters use the dedicated repeater telemetry tracking list",
+        )
 
     if len(current) >= MAX_TRACKED_TELEMETRY_CONTACTS:
         names = await _resolve_names(current)