1 files changed, 8 insertions, 1 deletions
diff --git a/spec/ruby/library/openstruct/method_missing_spec.rb b/spec/ruby/library/openstruct/method_missing_spec.rb
index eefe30661a..fe955791af 100644
--- a/spec/ruby/library/openstruct/method_missing_spec.rb
+++ b/spec/ruby/library/openstruct/method_missing_spec.rb
@@ -32,10 +32,17 @@ describe "OpenStruct#method_missing when called with a method name ending in '='
 end
 
 describe "OpenStruct#method_missing when passed additional arguments" do
-  it "raises a NoMethodError" do
+  it "raises a NoMethodError when the key does not exist" do
     os = OpenStruct.new
     lambda { os.method_missing(:test, 1, 2, 3) }.should raise_error(NoMethodError)
   end
+
+  ruby_version_is "2.7" do
+    it "raises an ArgumentError when the key exists" do
+      os = OpenStruct.new(test: 20)
+      lambda { os.method_missing(:test, 1, 2, 3) }.should raise_error(ArgumentError)
+    end
+  end
 end
 
 describe "OpenStruct#method_missing when not passed any additional arguments" do