1 files changed, 1 insertions, 1 deletions
diff --git a/src/main.h b/src/main.h
index 3a3687ec1d..09f22471d6 100644
--- a/src/main.h
+++ b/src/main.h
@@ -25,6 +25,7 @@
 #include "tinyformat.h"
 #include "txmempool.h"
 #include "uint256.h"
+#include "undo.h"
 
 #include <algorithm>
 #include <exception>
@@ -129,7 +130,6 @@ static const uint64_t nMinDiskSpace = 52428800;
 
 
 class CBlockTreeDB;
-class CTxUndo;
 class CScriptCheck;
 class CValidationState;
 class CValidationInterface;