diff --git a/db/migrate/20190404132157_add_implicit_varchar_uuid_cast.rb b/db/migrate/20190404132157_add_implicit_varchar_uuid_cast.rb
deleted file mode 100644
index 2c874a7f1..000000000
--- a/db/migrate/20190404132157_add_implicit_varchar_uuid_cast.rb
+++ /dev/null
@@ -1,25 +0,0 @@
-class AddImplicitVarcharUuidCast < ActiveRecord::Migration[5.2]
-  def up
-    if on_postgresql?
-      ActiveRecord::Base.connection.execute <<~SQL
-        CREATE CAST (varchar AS uuid)
-        WITH INOUT
-        AS IMPLICIT
-      SQL
-    end
-  end
-
-  def down
-    if on_postgresql?
-      ActiveRecord::Base.connection.execute <<~SQL
-        DROP CAST (varchar AS uuid)
-      SQL
-    end
-  end
-
-  private
-
-  def on_postgresql?
-    ActiveRecord::Base.connection.adapter_name == 'PostgreSQL'
-  end
-end
diff --git a/extra/dynflow-debug.sh b/extra/dynflow-debug.sh
index 184f29503..b7bd544cc 100755
--- a/extra/dynflow-debug.sh
+++ b/extra/dynflow-debug.sh
@@ -31,9 +31,9 @@ add_files /var/log/foreman/dynflow_executor*.output*
 # Foreman Tasks fast export (Postgresql only; for HTML version use foreman-rake foreman_tasks:export_tasks)
 
 if [ "$FOREMAN_DB_ADAPTER" == "postgresql" ]; then
-    export_csv "select dynflow_execution_plans.* from foreman_tasks_tasks join dynflow_execution_plans on (foreman_tasks_tasks.external_id = dynflow_execution_plans.uuid) where foreman_tasks_tasks.started_at > 'now'::timestamp - '${DYNFLOW_EXPORT_MONTHS:-1} months'::interval limit ${DYNFLOW_EXPORT_LIMIT:-100000}" "$DIR/dynflow_execution_plans.csv"
-    export_csv "select dynflow_actions.* from foreman_tasks_tasks join dynflow_actions on (foreman_tasks_tasks.external_id = dynflow_actions.execution_plan_uuid) where foreman_tasks_tasks.started_at > 'now'::timestamp - '${DYNFLOW_EXPORT_MONTHS:-1} months'::interval limit ${DYNFLOW_EXPORT_LIMIT:-100000}" "$DIR/dynflow_actions.csv"
-    export_csv "select dynflow_steps.* from foreman_tasks_tasks join dynflow_steps on (foreman_tasks_tasks.external_id = dynflow_steps.execution_plan_uuid) where foreman_tasks_tasks.started_at > 'now'::timestamp - '${DYNFLOW_EXPORT_MONTHS:-1} months'::interval limit ${DYNFLOW_EXPORT_LIMIT:-100000}" "$DIR/dynflow_steps.csv"
+    export_csv "select dynflow_execution_plans.* from foreman_tasks_tasks join dynflow_execution_plans on (foreman_tasks_tasks.external_id = dynflow_execution_plans.uuid::varchar) where foreman_tasks_tasks.started_at > 'now'::timestamp - '${DYNFLOW_EXPORT_MONTHS:-1} months'::interval limit ${DYNFLOW_EXPORT_LIMIT:-100000}" "$DIR/dynflow_execution_plans.csv"
+    export_csv "select dynflow_actions.* from foreman_tasks_tasks join dynflow_actions on (foreman_tasks_tasks.external_id = dynflow_actions.execution_plan_uuid::varchar) where foreman_tasks_tasks.started_at > 'now'::timestamp - '${DYNFLOW_EXPORT_MONTHS:-1} months'::interval limit ${DYNFLOW_EXPORT_LIMIT:-100000}" "$DIR/dynflow_actions.csv"
+    export_csv "select dynflow_steps.* from foreman_tasks_tasks join dynflow_steps on (foreman_tasks_tasks.external_id = dynflow_steps.execution_plan_uuid::varchar) where foreman_tasks_tasks.started_at > 'now'::timestamp - '${DYNFLOW_EXPORT_MONTHS:-1} months'::interval limit ${DYNFLOW_EXPORT_LIMIT:-100000}" "$DIR/dynflow_steps.csv"
     export_csv "select * from dynflow_schema_info" "$DIR/dynflow_schema_info.csv"
     export_csv "select * from foreman_tasks_tasks limit ${DYNFLOW_EXPORT_LIMIT:-100000}" "$DIR/foreman_tasks_tasks.csv"
 fi
diff --git a/lib/foreman_tasks/cleaner.rb b/lib/foreman_tasks/cleaner.rb
index 89a0116fe..4832556ad 100644
--- a/lib/foreman_tasks/cleaner.rb
+++ b/lib/foreman_tasks/cleaner.rb
@@ -192,9 +192,15 @@ def with_batches(source, name)
     end
 
     def orphaned_dynflow_tasks
+      dynflow_plan_uuid_attribute = "dynflow_execution_plans.uuid"
+      if ActiveRecord::Base.connection.adapter_name == 'PostgreSQL'
+        # typecast the UUID attribute for Postgres
+        dynflow_plan_uuid_attribute += "::varchar"
+      end
+
       db = ForemanTasks.dynflow.world.persistence.adapter.db
       db.fetch("select dynflow_execution_plans.uuid from dynflow_execution_plans left join "\
-               "foreman_tasks_tasks on (dynflow_execution_plans.uuid = foreman_tasks_tasks.external_id) "\
+               "foreman_tasks_tasks on (#{dynflow_plan_uuid_attribute} = foreman_tasks_tasks.external_id) "\
                "where foreman_tasks_tasks.id IS NULL")
     end
 
diff --git a/test/unit/cleaner_test.rb b/test/unit/cleaner_test.rb
index c021f5284..7ea66274a 100644
--- a/test/unit/cleaner_test.rb
+++ b/test/unit/cleaner_test.rb
@@ -32,6 +32,27 @@ class TasksTest < ActiveSupport::TestCase
                   .find_execution_plans(filters: { 'uuid' => tasks_to_keep.map(&:external_id) }).size.must_equal tasks_to_keep.size
     end
 
+    describe "#orphaned_dynflow_tasks" do
+      # We can't use transactional tests because we're using Sequel for the cleanup query
+      self.use_transactional_tests = false
+      before do
+        skip "Sqlite is running testing Dynlfow DB in memory" if ActiveRecord::Base.connection.adapter_name == 'SQLite'
+        @existing_task = FactoryBot.create(:dynflow_task, :user_create_task)
+        @missing_task = FactoryBot.create(:dynflow_task, :user_create_task)
+        @cleaner = ForemanTasks::Cleaner.new(filter: "id ^ (#{@existing_task.id}, #{@missing_task.id})")
+        @missing_task.destroy
+      end
+
+      after do
+        @cleaner.delete if @cleaner
+      end
+
+      it 'is able to find orphaned execution plans (without corresponding task object)' do
+        assert(@cleaner.orphaned_dynflow_tasks.any? { |t| t[:uuid] == @missing_task.external_id })
+        assert_not(@cleaner.orphaned_dynflow_tasks.any? { |t| t[:uuid] == @existing_task.external_id })
+      end
+    end
+
     it 'deletes all tasks matching the filter when the time limit is not specified' do
       cleaner = ForemanTasks::Cleaner.new(:filter => 'label = "Actions::User::Create"')
       tasks_to_delete = [FactoryBot.create(:dynflow_task, :user_create_task),