diff --git a/libguile/whippet-embedder.h b/libguile/whippet-embedder.h
index 82e177936..c2b993c01 100644
--- a/libguile/whippet-embedder.h
+++ b/libguile/whippet-embedder.h
@@ -65,7 +65,11 @@ gc_is_valid_conservative_ref_displacement (uintptr_t displacement) {
 static inline int gc_extern_space_visit (struct gc_extern_space *space,
                                          struct gc_edge edge,
                                          struct gc_ref ref) {
+#if GC_CONSERVATIVE_TRACE
+  return 0;
+#else
   GC_CRASH ();
+#endif
 }
 static inline void gc_extern_space_start_gc (struct gc_extern_space *space,
                                              int is_minor_gc) {