diff --git a/src/backend/storage/ipc/latch.c b/src/backend/storage/ipc/latch.c
index 9def8a12d3ddfd2e5b0af7cc7a473e29edd9d04e..fe5113ebd70e61c4d1870cc7f2f2f039dcd368e7 100644
--- a/src/backend/storage/ipc/latch.c
+++ b/src/backend/storage/ipc/latch.c
@@ -260,7 +260,8 @@ OwnLatch(volatile Latch *latch)
 #endif
 
 	if (latch->owner_pid != 0)
-		elog(ERROR, "latch already owned");
+		elog(ERROR, "latch already owned by pid %d (is_set: %d)",
+			 latch->owner_pid, (int) latch->is_set);
 
 	latch->owner_pid = MyProcPid;
 }