diff --git a/gc.c b/gc.c
index c2889a78c2..dc17f3bf31 100644
--- a/gc.c
+++ b/gc.c
@@ -3007,6 +3007,20 @@ rb_gc_location(VALUE value)
     return rb_gc_impl_location(rb_gc_get_objspace(), value);
 }
 
+void
+rb_gc_prepare_heap_process_object(VALUE obj)
+{
+    switch (BUILTIN_TYPE(obj)) {
+      case T_STRING:
+        // Precompute the string coderange. This both save time for when it will be
+        // eventually needed, and avoid mutating heap pages after a potential fork.
+        rb_enc_str_coderange(obj);
+        break;
+      default:
+        break;
+    }
+}
+
 void
 rb_gc_prepare_heap(void)
 {
diff --git a/gc/default.c b/gc/default.c
index d28c8aa553..dac7aaeed6 100644
--- a/gc/default.c
+++ b/gc/default.c
@@ -6763,12 +6763,8 @@ gc_set_candidate_object_i(void *vstart, void *vend, size_t stride, void *data)
               case T_NONE:
               case T_ZOMBIE:
                 break;
-              case T_STRING:
-                // precompute the string coderange. This both save time for when it will be
-                // eventually needed, and avoid mutating heap pages after a potential fork.
-                rb_enc_str_coderange(v);
-                // fall through
               default:
+                rb_gc_prepare_heap_process_object(v);
                 if (!RVALUE_OLD_P(objspace, v) && !RVALUE_WB_UNPROTECTED(objspace, v)) {
                     RVALUE_AGE_SET_CANDIDATE(objspace, v);
                 }
diff --git a/gc/gc.h b/gc/gc.h
index d5b07faf92..1cacf8a2a5 100644
--- a/gc/gc.h
+++ b/gc/gc.h
@@ -42,6 +42,7 @@ uint32_t rb_gc_get_shape(VALUE obj);
 void rb_gc_set_shape(VALUE obj, uint32_t shape_id);
 uint32_t rb_gc_rebuild_shape(VALUE obj, size_t heap_id);
 size_t rb_obj_memsize_of(VALUE obj);
+void rb_gc_prepare_heap_process_object(VALUE obj);
 RUBY_SYMBOL_EXPORT_END
 
 void rb_ractor_finish_marking(void);