diff --git a/tasks/postgresql-config.yml b/tasks/postgresql-config.yml
index 6787b5d..115f1ab 100644
--- a/tasks/postgresql-config.yml
+++ b/tasks/postgresql-config.yml
@@ -109,7 +109,7 @@
   - name: Restart the postgresql server after changing parameters that need a restart
     service: name=postgresql state=restarted
     when:
-      - restart_postgresql is changed
+      - restart_postgresql is defined and restart_postgresql is changed
     ignore_errors: True
     tags: [ 'postgresql', 'postgres', 'pg_hba', 'pg_conf' ]
 
@@ -246,7 +246,7 @@
   - name: Restart the postgresql server after changing parameters that need a restart
     service: name='postgresql-{{ psql_version }}' state=restarted
     when:
-      - restart_postgresql is changed
+      - restart_postgresql is defined and restart_postgresql is changed
     ignore_errors: True
     tags: [ 'postgresql', 'postgres', 'pg_hba', 'pg_conf' ]