diff --git a/lib/en57/pg_repository.rb b/lib/en57/pg_repository.rb
index 03b963a..83ec37f 100644
--- a/lib/en57/pg_repository.rb
+++ b/lib/en57/pg_repository.rb
@@ -33,10 +33,13 @@ module En57
       ] = fail_if_events_match unless fail_if_events_match.empty?
       append_condition[:after] = after unless after.nil?
 
-      in_serializable_transaction do
-        @connection.exec_params(
+      with_serializable_transaction do |connection|
+        connection.exec_params(
           "SELECT append_events($1::event_with_tags[], $2::jsonb)",
-          [@array_encoder.encode(event_records), JSON.generate(append_condition)],
+          [
+            @array_encoder.encode(event_records),
+            JSON.generate(append_condition),
+          ],
         )
       end
     rescue PG::Error => e
@@ -51,12 +54,12 @@ module En57
     def read(query)
       criteria = query.encoded_criteria.map { |item| JSON.generate(item) }
 
-      @connection
-        .exec_params(
+      with_connection do |connection|
+        connection.exec_params(
           "SELECT id, type, data, meta, tags FROM read_events($1::jsonb[])",
           [@array_encoder.encode(criteria)],
         )
-        .map do |row|
+      end.map do |row|
           Event.new(
             id: row.fetch("id"),
             type: row.fetch("type"),
@@ -68,13 +71,19 @@ module En57
 
     private
 
-    def in_serializable_transaction
-      @connection.exec("BEGIN ISOLATION LEVEL SERIALIZABLE")
-      yield
-      @connection.exec("COMMIT")
-    rescue StandardError
-      @connection.exec("ROLLBACK")
-      raise
+    def with_serializable_transaction
+      with_connection do |connection|
+        connection.exec("BEGIN ISOLATION LEVEL SERIALIZABLE")
+        yield connection
+        connection.exec("COMMIT")
+      rescue StandardError
+        connection.exec("ROLLBACK")
+        raise
+      end
+    end
+
+    def with_connection
+      yield @connection
     end
   end
 end