diff --git a/fs/nfs/callback.c b/fs/nfs/callback.c
index 0d784f6..66648dd 100644
--- a/fs/nfs/callback.c
+++ b/fs/nfs/callback.c
@@ -172,7 +172,7 @@
 static int nfs_callback_authenticate(struct svc_rqst *rqstp)
 {
 	struct nfs_client *clp;
-	char buf[RPC_MAX_ADDRBUFLEN];
+	RPC_IFDEBUG(char buf[RPC_MAX_ADDRBUFLEN]);
 
 	/* Don't talk to strangers */
 	clp = nfs_find_client(svc_addr(rqstp), 4);