diff --git a/lib/ostruct.rb b/lib/ostruct.rb
index 45ebb80..b1ad116 100644
--- a/lib/ostruct.rb
+++ b/lib/ostruct.rb
@@ -89,7 +89,7 @@ class OpenStruct
   def method_missing(mid, *args) # :nodoc:
     mname = mid.id2name
     len = args.length
-    if mname.chomp!('=')
+    if mname.chomp!('=') && mname != "[]"
       if len != 1
         raise ArgumentError, "wrong number of arguments (#{len} for 1)", caller(1)
       end
diff --git a/test/ostruct/test_ostruct.rb b/test/ostruct/test_ostruct.rb
index 5c140a4..7504e29 100644
--- a/test/ostruct/test_ostruct.rb
+++ b/test/ostruct/test_ostruct.rb
@@ -63,4 +63,15 @@ EOT
     assert_raise(TypeError) {o.a = 'z'}
     assert_equal('a', o.a)
   end
+
+  def test_method_missing_handles_square_bracket_equals
+    o = OpenStruct.new
+    assert_raise(NoMethodError) { o[:foo] = :bar }
+  end
+
+  def test_method_missing_handles_square_brackets
+    o = OpenStruct.new
+    assert_raise(NoMethodError) { o[:foo] }
+  end
+
 end