diff --git a/lib/std/c/openbsd.zig b/lib/std/c/openbsd.zig
index 48feaff428..5525aa18e6 100644
--- a/lib/std/c/openbsd.zig
+++ b/lib/std/c/openbsd.zig
@@ -34,4 +34,4 @@ pub const pthread_attr_t = extern struct {
 };
 
 pub extern "c" fn posix_memalign(memptr: *?*c_void, alignment: usize, size: usize) c_int;
-pub extern "c" fn malloc_usable_size(?*const c_void) usize;
+