diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index aa459188..31f339c2 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -88,4 +88,4 @@ jobs:
           done
           cat ${{ github.workspace }}/setup.sql | cockroach sql --insecure
       - name: Test
-        run: bundle exec rake test TESTOPTS='--profile=3 --verbose'
+        run: bundle exec rake test TESTOPTS='--profile=3 --verbose' TEST_FILES_AR=test/cases/adapters/postgresql/transaction_nested_test.rb
diff --git a/Gemfile b/Gemfile
index bb239f29..6ddda894 100644
--- a/Gemfile
+++ b/Gemfile
@@ -62,7 +62,6 @@ group :development, :test do
 
   # Gems used by the ActiveRecord test suite
   gem "bcrypt", "~> 3.1.18"
-  gem "mocha", "~> 1.14.0"
   gem "sqlite3", "~> 1.4.4"
 
   gem "minitest", "~> 5.15.0"
diff --git a/lib/active_record/connection_adapters/cockroachdb/transaction_manager.rb b/lib/active_record/connection_adapters/cockroachdb/transaction_manager.rb
index 8591f027..63f3e894 100644
--- a/lib/active_record/connection_adapters/cockroachdb/transaction_manager.rb
+++ b/lib/active_record/connection_adapters/cockroachdb/transaction_manager.rb
@@ -25,6 +25,7 @@ module TransactionManagerMonkeyPatch
         def within_new_transaction(isolation: nil, joinable: true, attempts: 0)
           super(isolation: isolation, joinable: joinable)
         rescue ActiveRecord::ConnectionNotEstablished => error
+          puts "IN RETRY CASE ! " * 5
           raise unless retryable? error
           raise if attempts >= @connection.max_transaction_retries
 
@@ -37,6 +38,7 @@ def within_new_transaction(isolation: nil, joinable: true, attempts: 0)
 
           within_new_transaction(isolation: isolation, joinable: joinable, attempts: attempts + 1) { yield }
         rescue ActiveRecord::StatementInvalid => error
+          puts "IN RETRY CASE ! " * 5
           raise unless retryable? error
           raise if attempts >= @connection.max_transaction_retries
 
@@ -46,6 +48,8 @@ def within_new_transaction(isolation: nil, joinable: true, attempts: 0)
         end
 
         def retryable?(error)
+          puts "========> In a serialization failure" if error.is_a? ActiveRecord::SerializationFailure
+          puts "========> In a serialization error" if serialization_error?(error)
           return true if serialization_error?(error)
           return true if error.is_a? ActiveRecord::SerializationFailure
           return retryable? error.cause if error.cause
diff --git a/test/cases/connection_adapters/type_test.rb b/test/cases/connection_adapters/type_test.rb
index 8b47004a..8aca51cf 100644
--- a/test/cases/connection_adapters/type_test.rb
+++ b/test/cases/connection_adapters/type_test.rb
@@ -7,10 +7,9 @@ module CockroachDB
   module ConnectionAdapters
     class TypeTest < ActiveRecord::TestCase
       fixtures :accounts
-      class SqliteModel < ActiveRecord::Base
+      class FakeModel < ActiveRecord::Base
         establish_connection(
-          adapter:  "sqlite3",
-          database: "tmp/some"
+          adapter:  "fake"
         )
       end
       def test_type_can_be_used_with_various_db
@@ -19,8 +18,8 @@ def test_type_can_be_used_with_various_db
           ActiveRecord::Type.adapter_name_from(Account)
         )
         assert_equal(
-           :sqlite3,
-           ActiveRecord::Type.adapter_name_from(SqliteModel)
+           :fake,
+           ActiveRecord::Type.adapter_name_from(FakeModel)
         )
       end
     end
diff --git a/test/excludes/ActiveRecord/PostgresqlTransactionNestedTest.rb b/test/excludes/ActiveRecord/PostgresqlTransactionNestedTest.rb
index 22838c71..35ae977f 100644
--- a/test/excludes/ActiveRecord/PostgresqlTransactionNestedTest.rb
+++ b/test/excludes/ActiveRecord/PostgresqlTransactionNestedTest.rb
@@ -1,2 +1,14 @@
-exclude :test_deadlock_raises_Deadlocked_inside_nested_SavepointTransaction, "Causes CI to hand. Skip while debugging."
-exclude :test_unserializable_transaction_raises_SerializationFailure_inside_nested_SavepointTransaction, "Causes CI to hand. Skip while debugging."
+
+# > In CRDB SERIALIZABLE, reads block on in-progress writes for
+# > as long as those writes are in progress. However, PG does
+# > not have this "read block on write" behavior, and so rather
+# > than allowing the left-hand-side to execute, it must instead
+# > abort that transaction. Both are valid ways to implement SERIALIZABLE.
+#
+# See discussion: https://github.com/cockroachdb/activerecord-cockroachdb-adapter/pull/333
+message = "SERIALIZABLE transactions are different in CockroachDB."
+
+# exclude :test_deadlock_raises_Deadlocked_inside_nested_SavepointTransaction, message
+# exclude :test_unserializable_transaction_raises_SerializationFailure_inside_nested_SavepointTransaction, message
+exclude :test_SerializationFailure_inside_nested_SavepointTransaction_is_recoverable, message
+exclude :test_deadlock_inside_nested_SavepointTransaction_is_recoverable, message