diff --git a/class.c b/class.c
index bcdaa82..885cb80 100644
--- a/class.c
+++ b/class.c
@@ -2024,6 +2024,13 @@ rb_prepend_module(VALUE klass, VALUE module)
                 /* During lazy sweeping, the entry could be a dead object that
                  * has not yet been swept. */
                 if (!rb_objspace_garbage_object_p(subclass)) {
+                    /* An origin iclass backfilled by a previous prepend is
+                     * registered in the subclasses list only so that method
+                     * cache invalidation can reach it. The module is inserted
+                     * between the includer's iclass and that origin when the
+                     * includer's iclass is visited, so visiting the origin too
+                     * would insert the module a second time. */
+                    if (RICLASS_IS_ORIGIN_P(subclass)) continue;
                     if (klass_had_no_origin && klass_origin_m_tbl == RCLASS_M_TBL(subclass)) {
                         // backfill an origin iclass to handle refinements and future prepends
                         rb_id_table_foreach(RCLASS_M_TBL(subclass), clear_module_cache_i, (void *)subclass);
diff --git a/test/ruby/test_module.rb b/test/ruby/test_module.rb
index 10d0e67..adf0220 100644
--- a/test/ruby/test_module.rb
+++ b/test/ruby/test_module.rb
@@ -2858,6 +2858,27 @@ def test_prepend_no_duplication
     assert_equal([m, c], c.ancestors[0, 2], "should never duplicate")
   end
 
+  def test_prepend_to_included_module_multiple_times
+    m = labeled_module("M")
+    c = labeled_class("C") {include m}
+    m0 = labeled_module("M0")
+    m1 = labeled_module("M1")
+    m2 = labeled_module("M2")
+    m.prepend m0
+    m.prepend m1
+    m.prepend m2
+    assert_equal([c, m2, m1, m0, m, Object], c.ancestors[0, 6], "should never duplicate")
+
+    base = Module.new {def m; [:base] end}
+    h = Module.new {include base}
+    view = Class.new {include h}
+    p1 = Module.new {def m; [:p1] + super end}
+    p2 = Module.new {def m; [:p2] + super end}
+    h.prepend p1
+    h.prepend p2
+    assert_equal([:p2, :p1, :base], view.new.m)
+  end
+
   def test_prepend_in_superclass
     m = labeled_module("M")
     c1 = labeled_class("C1")