diff --git a/CHANGELOG.md b/CHANGELOG.md
index 25eacd6..96343e7 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,6 @@
 # main [(unreleased)](https://github.com/fastruby/next_rails/compare/v1.5.0...main)
 
+- [BUGFIX: Fix Ruby 2.3 compatibility in DeprecationTracker#normalized_deprecation_messages](https://github.com/fastruby/next_rails/pull/180)
 - [BUGFIX: example](https://github.com/fastruby/next_rails/pull/<number>)
 
 - [BUGFIX: Compare mode now checks only buckets the current process ran, fixing parallel test support](https://github.com/fastruby/next_rails/pull/179)
diff --git a/lib/deprecation_tracker.rb b/lib/deprecation_tracker.rb
index 08379c6..7828dc9 100644
--- a/lib/deprecation_tracker.rb
+++ b/lib/deprecation_tracker.rb
@@ -184,7 +184,7 @@ def compare
 
     changed_buckets = []
 
-    normalized_deprecation_messages.each do |bucket, messages|
+    deprecation_messages.each do |bucket, messages|
       if stored[bucket] != messages
         changed_buckets << bucket
       end
@@ -252,7 +252,7 @@ def normalized_deprecation_messages
 
       # not using `to_h` here to support older ruby versions
       {}.tap do |h|
-        normalized.reject {|_key, value| value.empty? }.sort_by {|key, _value| key }.each do |k ,v|
+        normalized.reject {|_key, value| value.empty? }.sort_by {|key, _value| key }.each do |k, v|
           h[k] = v
         end
       end
diff --git a/spec/deprecation_tracker_spec.rb b/spec/deprecation_tracker_spec.rb
index 193afd0..0302117 100644
--- a/spec/deprecation_tracker_spec.rb
+++ b/spec/deprecation_tracker_spec.rb
@@ -226,6 +226,60 @@
     end
   end
 
+  describe "#normalized_deprecation_messages" do
+    it "merges stored and current messages" do
+      setup_tracker = DeprecationTracker.new(shitlist_path)
+      setup_tracker.bucket = "bucket 1"
+      setup_tracker.add("a")
+      setup_tracker.save
+
+      subject = DeprecationTracker.new(shitlist_path)
+      subject.bucket = "bucket 2"
+      subject.add("b")
+
+      normalized = subject.normalized_deprecation_messages
+      expect(normalized).to eq(
+        "bucket 1" => ["a"],
+        "bucket 2" => ["b"]
+      )
+    end
+
+    it "sorts messages per bucket" do
+      subject = DeprecationTracker.new(shitlist_path)
+      subject.bucket = "bucket 1"
+      subject.add("c")
+      subject.add("a")
+      subject.add("b")
+
+      normalized = subject.normalized_deprecation_messages
+      expect(normalized["bucket 1"]).to eq(["a", "b", "c"])
+    end
+
+    it "rejects empty buckets" do
+      setup_tracker = DeprecationTracker.new(shitlist_path)
+      setup_tracker.bucket = "bucket 1"
+      setup_tracker.add("a")
+      setup_tracker.save
+
+      subject = DeprecationTracker.new(shitlist_path)
+      # Don't add anything, just read
+
+      normalized = subject.normalized_deprecation_messages
+      expect(normalized).to eq("bucket 1" => ["a"])
+    end
+
+    it "sorts by bucket name" do
+      subject = DeprecationTracker.new(shitlist_path)
+      subject.bucket = "z_bucket"
+      subject.add("a")
+      subject.bucket = "a_bucket"
+      subject.add("b")
+
+      normalized = subject.normalized_deprecation_messages
+      expect(normalized.keys).to eq(["a_bucket", "z_bucket"])
+    end
+  end
+
   describe "#after_run" do
     let(:shitlist_path) { "some_path" }