diff --git a/lib/taste_tester/state.rb b/lib/taste_tester/state.rb
index 5b3dcc51..496694e2 100644
--- a/lib/taste_tester/state.rb
+++ b/lib/taste_tester/state.rb
@@ -145,12 +145,9 @@ def merge(vals)
         state = {}
       end
       state.merge!(vals)
-      ff = File.open(
-        TasteTester::Config.ref_file,
-        'w',
-      )
-      ff.write(state.to_json)
-      ff.close
+      File.open(TasteTester::Config.ref_file, 'w') do |ff|
+        ff.write(state.to_json)
+      end
     rescue StandardError => e
       logger.error('Unable to write the reffile')
       logger.debug(e)
diff --git a/spec/taste-tester_spec.rb b/spec/taste-tester_spec.rb
new file mode 100644
index 00000000..c01f8c40
--- /dev/null
+++ b/spec/taste-tester_spec.rb
@@ -0,0 +1,23 @@
+require "spec_helper"
+require 'taste_tester/state'
+
+describe TasteTester::State do
+
+  it "should serialize changes correctly" do
+    # initializing a state object creates a directory
+    # so let's pretend it already exists.
+    allow(File).to receive(:directory?).and_return(true)
+
+    # original state file says ssl -> true
+    allow(File).to receive(:read).and_return('{"ssl": true}')
+    @s = TasteTester::State.new
+
+    expect(@s.ssl).to eq(true)
+
+    @buffer = StringIO.new()
+    allow(File).to receive(:open).and_yield(@buffer)
+    @s.ssl = false
+    expect(@buffer.string).to eq('{"ssl":false}')
+  end
+
+end