diff --git a/include/linux/ctype.h b/include/linux/ctype.h
index afa363922..6dec944a3 100644
--- a/include/linux/ctype.h
+++ b/include/linux/ctype.h
@@ -15,7 +15,7 @@
 #define _X	0x40	/* hex digit */
 #define _SP	0x80	/* hard space (0x20) */
 
-extern unsigned char _ctype[];
+extern const unsigned char _ctype[];
 
 #define __ismask(x) (_ctype[(int)(unsigned char)(x)])
 
diff --git a/lib/ctype.c b/lib/ctype.c
index 6ed0468a2..dffe56372 100644
--- a/lib/ctype.c
+++ b/lib/ctype.c
@@ -29,7 +29,7 @@
 
 #include <linux/ctype.h>
 
-unsigned char _ctype[] = {
+const unsigned char _ctype[] = {
 _C,_C,_C,_C,_C,_C,_C,_C,			/* 0-7 */
 _C,_C|_S,_C|_S,_C|_S,_C|_S,_C|_S,_C,_C,		/* 8-15 */
 _C,_C,_C,_C,_C,_C,_C,_C,			/* 16-23 */