diff --git a/libc/include/strings.h b/libc/include/strings.h
index ae261cf..1253006 100644
--- a/libc/include/strings.h
+++ b/libc/include/strings.h
@@ -41,22 +41,23 @@
 
 #include <sys/types.h>
 #include <sys/cdefs.h>
+#include <xlocale.h>
 
 __BEGIN_DECLS
 #if defined(__BIONIC_FORTIFY)
-#define bcopy(b1, b2, len) \
-  (void)(__builtin___memmove_chk((b2), (b1), (len), __bos0(b2)))
-#define bzero(b, len) \
-  (void)(__builtin___memset_chk((b), '\0', (len), __bos0(b)))
+#define bcopy(b1, b2, len) (void)(__builtin___memmove_chk((b2), (b1), (len), __bos0(b2)))
+#define bzero(b, len) (void)(__builtin___memset_chk((b), '\0', (len), __bos0(b)))
 #else
 #define bcopy(b1, b2, len) (void)(__builtin_memmove((b2), (b1), (len)))
 #define bzero(b, len) (void)(__builtin_memset((b), '\0', (len)))
 #endif
 
+int ffs(int);
 
-int	 ffs(int);
-int	 strcasecmp(const char *, const char *);
-int	 strncasecmp(const char *, const char *, size_t);
+int strcasecmp(const char*, const char*) __purefunc;
+int strcasecmp_l(const char*, const char*, locale_t) __purefunc;
+int strncasecmp(const char*, const char*, size_t) __purefunc;
+int strncasecmp_l(const char*, const char*, size_t, locale_t) __purefunc;
 
 __END_DECLS