diff --git a/test/tests/test_find_return_value.rb b/test/tests/test_find_return_value.rb
index 0d89cd94412b8e7c9893ca58db22eaebdd9bd0c0..da29ef967b5d933bbcd7a46506eaecc3e8a7e609 100644
--- a/test/tests/test_find_return_value.rb
+++ b/test/tests/test_find_return_value.rb
@@ -89,6 +89,19 @@ class FindReturnValueTests < Test::Unit::TestCase
     RUBY
   end
 
+  def test_iassgn_as_implicit_return
+    env = SexpProcessor::Environment.new
+    env[Sexp.new(:ivar, :@y)] = Sexp.new(:lit, 2)
+
+    assert_returns '1', <<-RUBY, env
+      def x
+        @y = 1
+      end
+    RUBY
+
+    assert_equal env[Sexp.new(:ivar, :@y)], Sexp.new(:lit, 1)
+  end
+
   def test_local_aliasing
     assert_returns "'a'", <<-RUBY
       def x