diff --git a/src/Terrain.cc b/src/Terrain.cc
index 1d89ca9c9aa17bb1bed44f3b91bfb52c029dbeaf..2ee3f25f856ce30593eaf1abd09fb0feb4e48434 100644
--- a/src/Terrain.cc
+++ b/src/Terrain.cc
@@ -196,6 +196,8 @@ QString TerrainBatchManager::_stateToString(State state)
     case State::Downloading:
         return QStringLiteral("Downloading");
     }
+
+    return QStringLiteral("State unknown");
 }
 
 ElevationProvider::ElevationProvider(QObject* parent)