diff --git a/src/include/utils/snapmgr.h b/src/include/utils/snapmgr.h
index ab953669bf2c73c806a1f26aaae211f8714c879b..86c48d9c8eff6ff90bb9635a57d60c2bd9aa4597 100644
--- a/src/include/utils/snapmgr.h
+++ b/src/include/utils/snapmgr.h
@@ -58,7 +58,7 @@ extern bool FirstSnapshotSet;
 
 extern TransactionId TransactionXmin;
 extern TransactionId RecentXmin;
-extern TransactionId RecentGlobalXmin;
+extern PGDLLIMPORT TransactionId RecentGlobalXmin;
 extern TransactionId RecentGlobalDataXmin;
 
 extern Snapshot GetTransactionSnapshot(void);