diff --git a/libc/include/sys/cdefs.h b/libc/include/sys/cdefs.h
index 3b058e8..63e782e 100644
--- a/libc/include/sys/cdefs.h
+++ b/libc/include/sys/cdefs.h
@@ -102,13 +102,12 @@
 #endif	/* !(__STDC__ || __cplusplus) */
 
 #define __always_inline __attribute__((__always_inline__))
+#define __attribute_const__ __attribute__((__const__))
+#define __attribute_pure__ __attribute__((__pure__))
 #define __dead __attribute__((__noreturn__))
 #define __noreturn __attribute__((__noreturn__))
-#define __mallocfunc  __attribute__((malloc))
+#define __mallocfunc  __attribute__((__malloc__))
 #define __packed __attribute__((__packed__))
-#define __pure __attribute__((__const__))
-#define __pure2 __attribute__((__const__)) /* Android-added: used by FreeBSD libm */
-#define __purefunc    __attribute__((pure))
 #define __unused __attribute__((__unused__))
 #define __used __attribute__((__used__))
 
diff --git a/libc/include/sys/endian.h b/libc/include/sys/endian.h
index b9e4758..de172fe 100644
--- a/libc/include/sys/endian.h
+++ b/libc/include/sys/endian.h
@@ -49,10 +49,10 @@
 
 /* glibc compatibility. */
 __BEGIN_DECLS
-uint32_t htonl(uint32_t) __pure2 __INTRODUCED_IN(21);
-uint16_t htons(uint16_t) __pure2 __INTRODUCED_IN(21);
-uint32_t ntohl(uint32_t) __pure2 __INTRODUCED_IN(21);
-uint16_t ntohs(uint16_t) __pure2 __INTRODUCED_IN(21);
+uint32_t htonl(uint32_t) __attribute_const__ __INTRODUCED_IN(21);
+uint16_t htons(uint16_t) __attribute_const__ __INTRODUCED_IN(21);
+uint32_t ntohl(uint32_t) __attribute_const__ __INTRODUCED_IN(21);
+uint16_t ntohs(uint16_t) __attribute_const__ __INTRODUCED_IN(21);
 __END_DECLS
 
 #define htonl(x) __swap32(x)