diff --git a/aiida/backends/sqlalchemy/migrations/versions/7ca08c391c49_calc_job_option_attribute_keys.py b/aiida/backends/sqlalchemy/migrations/versions/7ca08c391c49_calc_job_option_attribute_keys.py
index fa45acd381..ca817ac4da 100644
--- a/aiida/backends/sqlalchemy/migrations/versions/7ca08c391c49_calc_job_option_attribute_keys.py
+++ b/aiida/backends/sqlalchemy/migrations/versions/7ca08c391c49_calc_job_option_attribute_keys.py
@@ -49,7 +49,7 @@ def upgrade():
 
     statement = text("""
         UPDATE db_dbnode
-        SET attributes = jsonb_set(attributes, '{environment_variables}', to_jsonb(attributes->>'custom_environment_variables'))
+        SET attributes = jsonb_set(attributes, '{environment_variables}', attributes->'custom_environment_variables')
         WHERE
             attributes ? 'custom_environment_variables' AND
             type = 'node.process.calculation.calcjob.CalcJobNode.';
@@ -60,7 +60,7 @@ def upgrade():
         -- custom_environment_variables -> environment_variables
 
         UPDATE db_dbnode
-        SET attributes = jsonb_set(attributes, '{resources}', to_jsonb(attributes->>'jobresource_params'))
+        SET attributes = jsonb_set(attributes, '{resources}', attributes->'jobresource_params')
         WHERE
             attributes ? 'jobresource_params' AND
             type = 'node.process.calculation.calcjob.CalcJobNode.';
@@ -71,7 +71,7 @@ def upgrade():
         -- jobresource_params -> resources
 
         UPDATE db_dbnode
-        SET attributes = jsonb_set(attributes, '{process_label}', to_jsonb(attributes->>'_process_label'))
+        SET attributes = jsonb_set(attributes, '{process_label}', attributes->'_process_label')
         WHERE
             attributes ? '_process_label' AND
             type like 'node.process.%';
@@ -82,7 +82,7 @@ def upgrade():
         -- _process_label -> process_label
 
         UPDATE db_dbnode
-        SET attributes = jsonb_set(attributes, '{parser_name}', to_jsonb(attributes->>'parser'))
+        SET attributes = jsonb_set(attributes, '{parser_name}', attributes->'parser')
         WHERE
             attributes ? 'parser' AND
             type = 'node.process.calculation.calcjob.CalcJobNode.';
diff --git a/aiida/backends/sqlalchemy/tests/test_migrations.py b/aiida/backends/sqlalchemy/tests/test_migrations.py
index ce64c434c1..9efebfc1fb 100644
--- a/aiida/backends/sqlalchemy/tests/test_migrations.py
+++ b/aiida/backends/sqlalchemy/tests/test_migrations.py
@@ -575,7 +575,6 @@ def setUpBeforeMigration(self):
 
     def test_attribute_key_changes(self):
         """Verify that the keys are successfully changed of the affected attributes."""
-        import ast
         from sqlalchemy.orm import Session  # pylint: disable=import-error,no-name-in-module
 
         DbNode = self.get_auto_base().classes.db_dbnode  # pylint: disable=invalid-name
@@ -590,15 +589,12 @@ def test_attribute_key_changes(self):
                 self.assertEqual(node_work.attributes.get(self.KEY_PROCESS_LABEL_NEW), self.process_label)
                 self.assertEqual(node_work.attributes.get(self.KEY_PROCESS_LABEL_OLD, not_found), not_found)
 
-                # The dictionaries need to be cast with ast.literal_eval, because the `get` will return a string
-                # representation of the dictionary that the attribute contains
                 node_calc = session.query(DbNode).filter(DbNode.id == self.node_calc_id).one()
                 self.assertEqual(node_calc.attributes.get(self.KEY_PROCESS_LABEL_NEW), self.process_label)
                 self.assertEqual(node_calc.attributes.get(self.KEY_PARSER_NAME_NEW), self.parser_name)
-                self.assertEqual(ast.literal_eval(node_calc.attributes.get(self.KEY_RESOURCES_NEW)), self.resources)
+                self.assertEqual(node_calc.attributes.get(self.KEY_RESOURCES_NEW), self.resources)
                 self.assertEqual(
-                    ast.literal_eval(node_calc.attributes.get(self.KEY_ENVIRONMENT_VARIABLES_NEW)),
-                    self.environment_variables)
+                    node_calc.attributes.get(self.KEY_ENVIRONMENT_VARIABLES_NEW), self.environment_variables)
                 self.assertEqual(node_calc.attributes.get(self.KEY_PROCESS_LABEL_OLD, not_found), not_found)
                 self.assertEqual(node_calc.attributes.get(self.KEY_PARSER_NAME_OLD, not_found), not_found)
                 self.assertEqual(node_calc.attributes.get(self.KEY_RESOURCES_OLD, not_found), not_found)