diff --git a/libc/include/bits/strcasecmp.h b/libc/include/bits/strcasecmp.h
index 7cb713e..df1a6b8 100644
--- a/libc/include/bits/strcasecmp.h
+++ b/libc/include/bits/strcasecmp.h
@@ -35,10 +35,10 @@
 
 __BEGIN_DECLS
 
-int strcasecmp(const char*, const char*) __purefunc;
-int strcasecmp_l(const char*, const char*, locale_t) __purefunc __INTRODUCED_IN(23);
-int strncasecmp(const char*, const char*, size_t) __purefunc;
-int strncasecmp_l(const char*, const char*, size_t, locale_t) __purefunc __INTRODUCED_IN(23);
+int strcasecmp(const char*, const char*) __attribute_pure__;
+int strcasecmp_l(const char*, const char*, locale_t) __attribute_pure__ __INTRODUCED_IN(23);
+int strncasecmp(const char*, const char*, size_t) __attribute_pure__;
+int strncasecmp_l(const char*, const char*, size_t, locale_t) __attribute_pure__ __INTRODUCED_IN(23);
 
 __END_DECLS