diff --git a/src/UndoManager.cpp b/src/UndoManager.cpp
index 796a327dc..65644205c 100644
--- a/src/UndoManager.cpp
+++ b/src/UndoManager.cpp
@@ -236,7 +236,7 @@ void UndoManager::RemoveStates(size_t begin, size_t end)
 
       if (current > begin)
         --current;
-      if (saved > begin)
+      if (saved > static_cast<int>(begin))
         --saved;
    }