extern "C" {
#if FOLLY_HAVE_WEAK_SYMBOLS
-int rallocm(void**, size_t*, size_t, size_t, int) __attribute__((weak));
-int allocm(void**, size_t*, size_t, int) __attribute__((weak));
-int mallctl(const char*, void*, size_t*, void*, size_t) __attribute__((weak));
+int rallocm(void**, size_t*, size_t, size_t, int) __attribute__((__weak__));
+int allocm(void**, size_t*, size_t, int) __attribute__((__weak__));
+int mallctl(const char*, void*, size_t*, void*, size_t) __attribute__((__weak__));
#else
extern int (*rallocm)(void**, size_t*, size_t, size_t, int);
extern int (*allocm)(void**, size_t*, size_t, int);