diff --git a/vlib/builtin/builtin.c.v b/vlib/builtin/builtin.c.v
index a9680eed30e107..831f7d543173b4 100644
--- a/vlib/builtin/builtin.c.v
+++ b/vlib/builtin/builtin.c.v
@@ -394,7 +394,7 @@ fn _memory_panic(fname string, size isize) {
 	$if freestanding || vinix {
 		eprint('size') // TODO: use something more informative here
 	} $else {
-		C.fprintf(C.stderr, c'%ld', i64(size))
+		C.fprintf(C.stderr, c'%p', voidptr(size))
 	}
 	if size < 0 {
 		eprint(' < 0')