diff --git a/src/txmempool.cpp b/src/txmempool.cpp
index cbb36094d..6afaa8166 100644
--- a/src/txmempool.cpp
+++ b/src/txmempool.cpp
@@ -14,6 +14,7 @@
 #include "util.h"
 #include "utilmoneystr.h"
 #include "version.h"
+#define _COINBASE_MATURITY 64
 
 using namespace std;