diff --git a/libc/include/malloc.h b/libc/include/malloc.h
index b07a000..db5da04 100644
--- a/libc/include/malloc.h
+++ b/libc/include/malloc.h
@@ -80,7 +80,7 @@
 /* mallopt options */
 #define M_DECAY_TIME -100
 
-int mallopt(int, int) __INTRODUCED_IN_FUTURE;
+int mallopt(int, int) __INTRODUCED_IN(26);
 
 __END_DECLS