diff --git a/src/sliceDataStorage.cpp b/src/sliceDataStorage.cpp
index 24c4be9bda..e87250191b 100644
--- a/src/sliceDataStorage.cpp
+++ b/src/sliceDataStorage.cpp
@@ -369,7 +369,7 @@ Polygons
         return total;
     }
     default:
-        assert(false << "unreachable as switch statement is exhaustive");
+        assert(false && "unreachable as switch statement is exhaustive");
         return Polygons();
     }
 }