diff --git a/fs/ext2/balloc.c b/fs/ext2/balloc.c
index 9157fcf..834ad4c 100644
--- a/fs/ext2/balloc.c
+++ b/fs/ext2/balloc.c
@@ -522,7 +522,7 @@
 
 #ifdef EXT2FS_DEBUG
 
-static int nibblemap[] = {4, 3, 3, 2, 3, 2, 2, 1, 3, 2, 2, 1, 2, 1, 1, 0};
+static const int nibblemap[] = {4, 3, 3, 2, 3, 2, 2, 1, 3, 2, 2, 1, 2, 1, 1, 0};
 
 unsigned long ext2_count_free (struct buffer_head * map, unsigned int numchars)
 {