diff --git a/lib/rubygems/requirement.rb b/lib/rubygems/requirement.rb
index 4ebafb065f..02543cb14a 100644
--- a/lib/rubygems/requirement.rb
+++ b/lib/rubygems/requirement.rb
@@ -284,6 +284,11 @@ class Gem::Requirement
   def _tilde_requirements
     @_tilde_requirements ||= _sorted_requirements.select {|r| r.first == "~>" }
   end
+
+  def initialize_copy(other) # :nodoc:
+    @requirements = other.requirements.dup
+    super
+  end
 end
 
 class Gem::Version
diff --git a/test/rubygems/test_gem_requirement.rb b/test/rubygems/test_gem_requirement.rb
index 57d143180f..de0d11ec00 100644
--- a/test/rubygems/test_gem_requirement.rb
+++ b/test/rubygems/test_gem_requirement.rb
@@ -12,6 +12,14 @@ class TestGemRequirement < Gem::TestCase
     assert_equal [[">=", v(1)], ["<", v(2)]], r.requirements
   end
 
+  def test_initialize_copy
+    r = req("= 1.2")
+    r2 = r.dup
+
+    assert_equal r.requirements, r2.requirements
+    refute_same r.requirements, r2.requirements
+  end
+
   def test_equals2
     r = req "= 1.2"
     assert_equal r, r.dup