diff --git a/toonz/sources/include/tundo.h b/toonz/sources/include/tundo.h
index 25e34a9..24ee680 100644
--- a/toonz/sources/include/tundo.h
+++ b/toonz/sources/include/tundo.h
@@ -29,9 +29,9 @@
 class DVAPI TUndo {
 public:
   // To be called in the last of the block when undo
-  bool m_isLastInBlock;
+  bool m_isLastInBlock = true;
   // To be called in the last of the block when redo
-  bool m_isLastInRedoBlock;
+  bool m_isLastInRedoBlock = true;
 
 public:
   TUndo() {}