diff --git a/test/ruby/test_weakmap.rb b/test/ruby/test_weakmap.rb
index 35025c8201..32e321f48e 100644
--- a/test/ruby/test_weakmap.rb
+++ b/test/ruby/test_weakmap.rb
@@ -28,9 +28,10 @@ class TestWeakMap < Test::Unit::TestCase
     assert_raise(ArgumentError) {@wm[x] = :foo}
   end
 
-  def test_include?
-    m = __callee__[/test_(.*)/, 1]
-    k = "foo"
+  def assert_weak_include(m, k, n = 100)
+    if n > 0
+      return assert_weak_include(m, k, n-1)
+    end
     1.times do
       x = Object.new
       @wm[k] = x
@@ -38,6 +39,14 @@ class TestWeakMap < Test::Unit::TestCase
       assert_not_send([@wm, m, "FOO".downcase])
       x = nil
     end
+  end
+
+  def test_include?
+    m = __callee__[/test_(.*)/, 1]
+    k = "foo"
+    1.times do
+      assert_weak_include(m, k)
+    end
     GC.start
     # skip('TODO: failure introduced from r60440')
     assert_not_send([@wm, m, k])