diff --git a/rts/sm/Sanity.c b/rts/sm/Sanity.c
index 33cd47965cce935d83362e5b278338ad39dd466d..7ad902c2c9b23cf1911f82e6299dedf2a385ac05 100644
--- a/rts/sm/Sanity.c
+++ b/rts/sm/Sanity.c
@@ -357,7 +357,8 @@ checkClosure( const StgClosure* p )
     info = ACQUIRE_LOAD(&p->header.info);
 
     if (IS_FORWARDING_PTR(info)) {
-        barf("checkClosure: found EVACUATED closure %d", info->type);
+        ASSERT(LOOKS_LIKE_CLOSURE_PTR(info));
+        barf("checkClosure: found EVACUATED closure %u", GET_INFO((StgClosure*)UN_FORWARDING_PTR(info))->type);
     }
 
 #if defined(PROFILING)