diff --git a/sys/kern/kern_malloc.c b/sys/kern/kern_malloc.c
--- a/sys/kern/kern_malloc.c
+++ b/sys/kern/kern_malloc.c
@@ -1142,6 +1142,9 @@
 	case SLAB_COOKIE_MALLOC_LARGE:
 		size = malloc_large_size(slab);
 		break;
+	case SLAB_COOKIE_CONTIG_MALLOC:
+		size = round_page(contigmalloc_size(slab));
+		break;
 	default:
 		__assert_unreachable();
 		size = 0;