diff --git a/Rakefile b/Rakefile
index 07c4601..026acf6 100644
--- a/Rakefile
+++ b/Rakefile
@@ -18,6 +18,7 @@ task :compile do
   RubyMaven.exec('prepare-package')
   # after packaging the jrjackson-x.y.z.jar vendor jar dependencies
   Rake::Task['vendor_jars'].invoke
+  Rake::Task['verify_generated_files'].invoke
 end
 
 task :vendor_jars do
@@ -25,6 +26,17 @@ task :vendor_jars do
   Jars::Installer.vendor_jars!
 end
 
+# Fail the build if a file the gemspec lists is missing on disk. This stops a
+# broken gem from shipping, as happened with 0.5.1.
+task :verify_generated_files do
+  $LOAD_PATH.unshift(File.expand_path('lib', __dir__))
+  require 'jrjackson/build_info'
+  missing = JrJackson::BuildInfo.files.reject { |f| File.file?(f) }
+  unless missing.empty?
+    raise "These files are listed in the gemspec but missing after compile #{missing.join(', ')}"
+  end
+end
+
 desc "Clean build"
 task :clean do
   RubyMaven.exec('clean')
diff --git a/changelog.md b/changelog.md
index 4989519..9c7bffe 100644
--- a/changelog.md
+++ b/changelog.md
@@ -1,3 +1,11 @@
+v0.5.2
+  Fix packaging so the generated lib/jrjackson_jars.rb is included in the gem
+  List generated files explicitly instead of using Dir.glob so they are packaged even when generated after the gemspec is evaluated
+  Add a build step that fails when a file listed in the gemspec is missing
+
+v0.5.1
+  Upgrade jackson and jackson-databind to v2.21.4
+
 v0.5.0
   Upgrade jackson and jackson-databind to v2.21.2
   Require JRuby 9.4.14.0 and Java 11 toolchain for builds
diff --git a/lib/jrjackson/build_info.rb b/lib/jrjackson/build_info.rb
index dd31bd9..c4ea672 100644
--- a/lib/jrjackson/build_info.rb
+++ b/lib/jrjackson/build_info.rb
@@ -1,11 +1,11 @@
 module JrJackson
   module BuildInfo
     def self.version
-      '0.5.1'
+      '0.5.2'
     end
 
     def self.release_date
-      '2026-06-26'
+      '2026-07-07'
     end
 
     def self.files
@@ -30,12 +30,18 @@ def self.jar_version
 
     private
 
+    # Use an explicit list, not Dir.glob. The gemspec is evaluated at Rakefile
+    # load time, before rake compile regenerates these files, so a glob would
+    # drop them.
     def self.generated_files
-      Dir.glob( %w(pom.xml lib/jrjackson_jars.rb) )
+      %w(pom.xml lib/jrjackson_jars.rb)
     end
 
+    # Exclude jars from the glob. They are listed with their exact versions in
+    # generated_jar_files, so leftover jars from an older version are not
+    # packaged.
     def self.repo_files
-      Dir["lib/**/*"].select{ |f| File.file? f } + ["README.md", "jrjackson.gemspec", ]
+      Dir["lib/**/*"].select{ |f| File.file?(f) && !f.end_with?(".jar") } + ["README.md", "jrjackson.gemspec", ]
     end
 
     def self.generated_jar_files