diff --git a/test/ruby/test_shapes.rb b/test/ruby/test_shapes.rb
index 228e9a4913911a..7e3a77fdf24301 100644
--- a/test/ruby/test_shapes.rb
+++ b/test/ruby/test_shapes.rb
@@ -265,8 +265,13 @@ def test_run_out_of_shape_for_class
       c = Class.new
       c.instance_variable_set(:@a, 1)
       assert_equal(1, c.instance_variable_get(:@a))
+
       c.remove_instance_variable(:@a)
       assert_nil(c.instance_variable_get(:@a))
+
+      assert_raise(NameError) do
+        c.remove_instance_variable(:@a)
+      end
     end;
   end
 
@@ -290,6 +295,10 @@ class TooComplex < Hash
 
       tc.remove_instance_variable(:@a)
       assert_nil(tc.instance_variable_get(:@a))
+
+      assert_raise(NameError) do
+        tc.remove_instance_variable(:@a)
+      end
     end;
   end
 
diff --git a/variable.c b/variable.c
index 1e44775887f068..41c2b3650cda02 100644
--- a/variable.c
+++ b/variable.c
@@ -2199,7 +2199,9 @@ rb_obj_remove_instance_variable(VALUE obj, VALUE name)
       case T_MODULE:
         IVAR_ACCESSOR_SHOULD_BE_MAIN_RACTOR(id);
         if (rb_shape_obj_too_complex(obj)) {
-            st_delete(RCLASS_IV_HASH(obj), (st_data_t *)&id, (st_data_t *)&val);
+            if (!st_delete(RCLASS_IV_HASH(obj), (st_data_t *)&id, (st_data_t *)&val)) {
+                val = Qundef;
+            }
         }
         else {
             rb_shape_transition_shape_remove_ivar(obj, id, shape, &val);
@@ -2220,7 +2222,9 @@ rb_obj_remove_instance_variable(VALUE obj, VALUE name)
         if (rb_shape_obj_too_complex(obj)) {
             struct gen_ivtbl *ivtbl;
             if (rb_gen_ivtbl_get(obj, 0, &ivtbl)) {
-                st_delete(ivtbl->as.complex.table, (st_data_t *)&id, (st_data_t *)&val);
+                if (!st_delete(ivtbl->as.complex.table, (st_data_t *)&id, (st_data_t *)&val)) {
+                    val = Qundef;
+                }
             }
         }
         else {