diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c
index 87a3b489142bc585c2f7198604835f8e661d9a98..b913bf3ebcbbd0da80fd539aaf788140cf0f9ab8 100644
--- a/src/backend/access/transam/xlog.c
+++ b/src/backend/access/transam/xlog.c
@@ -7279,7 +7279,7 @@ StartupXLOG(void)
 				char		partialpath[MAXPGPATH];
 
 				XLogFilePath(origpath, EndOfLogTLI, endLogSegNo);
-				snprintf(partialfname, MAXPGPATH, "%s.partial", origfname);
+				snprintf(partialfname, MAXFNAMELEN, "%s.partial", origfname);
 				snprintf(partialpath, MAXPGPATH, "%s.partial", origpath);
 
 				/*