diff --git a/src/venus/fs.c b/src/venus/fs.c
index 9bdd1fba15..bbd819a85b 100644
--- a/src/venus/fs.c
+++ b/src/venus/fs.c
@@ -747,7 +747,7 @@ AclToString(struct Acl *acl)
 {
     static char mydata[AFS_PIOCTL_MAXSIZE];
     char tstring[AFS_PIOCTL_MAXSIZE];
-    char dfsstring[30];
+    char dfsstring[AFS_PIOCTL_MAXSIZE];
     struct AclEntry *tp;
 
     if (acl->dfs)