diff --git a/src/Resources/config/form_rule_additional_mappers.yml b/src/Resources/config/form_rule_additional_mappers.yml
index 6eac199..56eb600 100644
--- a/src/Resources/config/form_rule_additional_mappers.yml
+++ b/src/Resources/config/form_rule_additional_mappers.yml
@@ -1,14 +1,14 @@
 services:
   boekkooi.jquery_validation.mapper.iban:
     class: Boekkooi\Bundle\JqueryValidationBundle\Form\Rule\Mapping\IbanRule
-    arguments: [ %boekkooi.jquery_validation.additional.iban% ]
+    arguments: [ '%boekkooi.jquery_validation.additional.iban%' ]
     public: false
     tags:
      - { name: form_rule_constraint_mapper }
 
   boekkooi.jquery_validation.mapper.luhn:
     class: Boekkooi\Bundle\JqueryValidationBundle\Form\Rule\Mapping\LuhnRule
-    arguments: [ %boekkooi.jquery_validation.additional.luhn% ]
+    arguments: [ '%boekkooi.jquery_validation.additional.luhn%' ]
     public: false
     tags:
      - { name: form_rule_constraint_mapper }
@@ -16,23 +16,23 @@ services:
   boekkooi.jquery_validation.mapper.ip:
     class: Boekkooi\Bundle\JqueryValidationBundle\Form\Rule\Mapping\IpRule
     arguments:
-      - %boekkooi.jquery_validation.additional.ipv4%
-      - %boekkooi.jquery_validation.additional.ipv6%
-      - %boekkooi.jquery_validation.additional.one_or_other%
+      - '%boekkooi.jquery_validation.additional.ipv4%'
+      - '%boekkooi.jquery_validation.additional.ipv6%'
+      - '%boekkooi.jquery_validation.additional.one_or_other%'
     public: false
     tags:
      - { name: form_rule_constraint_mapper }
 
   boekkooi.jquery_validation.mapper.file:
     class: Boekkooi\Bundle\JqueryValidationBundle\Form\Rule\Mapping\FileRule
-    arguments: [ %boekkooi.jquery_validation.additional.accept% ]
+    arguments: [ '%boekkooi.jquery_validation.additional.accept%' ]
     public: false
     tags:
      - { name: form_rule_constraint_mapper }
 
   boekkooi.jquery_validation.mapper.pattern:
     class: Boekkooi\Bundle\JqueryValidationBundle\Form\Rule\Mapping\PatternRule
-    arguments: [ %boekkooi.jquery_validation.additional.pattern% ]
+    arguments: [ '%boekkooi.jquery_validation.additional.pattern%' ]
     public: false
     tags:
      - { name: form_rule_constraint_mapper }
diff --git a/src/Resources/config/form_rule_mappers.yml b/src/Resources/config/form_rule_mappers.yml
index d939559..d821c67 100644
--- a/src/Resources/config/form_rule_mappers.yml
+++ b/src/Resources/config/form_rule_mappers.yml
@@ -55,7 +55,7 @@ services:
 
   boekkooi.jquery_validation.mapper.is_boolean:
     class: Boekkooi\Bundle\JqueryValidationBundle\Form\Rule\Mapping\IsBooleanRule
-    arguments: [ %boekkooi.jquery_validation.additional.is_boolean% ]
+    arguments: [ '%boekkooi.jquery_validation.additional.is_boolean%' ]
     public: false
     tags:
      - { name: form_rule_constraint_mapper }
diff --git a/src/Resources/config/form_rule_processors.yml b/src/Resources/config/form_rule_processors.yml
index 8cf9e4d..f872c8a 100644
--- a/src/Resources/config/form_rule_processors.yml
+++ b/src/Resources/config/form_rule_processors.yml
@@ -13,7 +13,7 @@ services:
 
   boekkooi.jquery_validation.form.rule.processor.compound_copy_to_children:
     class: Boekkooi\Bundle\JqueryValidationBundle\Form\Rule\Processor\CompoundCopyToChildPass
-    arguments: [ %boekkooi.jquery_validation.additional.required_group% ]
+    arguments: [ '%boekkooi.jquery_validation.additional.required_group%' ]
     public: false
     tags:
       - { name: form_rule_processor, priority: 10 }
@@ -32,14 +32,14 @@ services:
 
   boekkooi.jquery_validation.form.rule.processor.datetime_array_transformer:
     class: Boekkooi\Bundle\JqueryValidationBundle\Form\Rule\Processor\DateTimeToArrayTransformerPass
-    arguments: [ %boekkooi.jquery_validation.additional.required_group% ]
+    arguments: [ '%boekkooi.jquery_validation.additional.required_group%' ]
     public: false
     tags:
      - { name: form_rule_processor, priority: 50 }
 
   boekkooi.jquery_validation.form.rule.processor.datetime_string_transformer:
     class: Boekkooi\Bundle\JqueryValidationBundle\Form\Rule\Processor\DateTimeToStringTransformerPass
-    arguments: [ %boekkooi.jquery_validation.additional.time% ]
+    arguments: [ '%boekkooi.jquery_validation.additional.time%' ]
     public: false
     tags:
      - { name: form_rule_processor, priority: 50 }
diff --git a/src/Resources/config/services.yml b/src/Resources/config/services.yml
index 954c2aa..f9c743e 100644
--- a/src/Resources/config/services.yml
+++ b/src/Resources/config/services.yml
@@ -9,31 +9,31 @@ parameters:
 
 services:
   boekkooi.jquery_validation.form.form_extension:
-    class: %boekkooi.jquery_validation.form.form_extension.class%
+    class: '%boekkooi.jquery_validation.form.form_extension.class%'
     arguments:
       - "@boekkooi.jquery_validation.rule_processor"
       - "@boekkooi.jquery_validation.rule_compiler"
       - "@boekkooi.jquery_validation.constraint_finder"
-      - %boekkooi.jquery_validation.enabled%
+      - '%boekkooi.jquery_validation.enabled%'
     tags:
       - { name: form.type_extension, alias: form, extended_type: Symfony\Component\Form\Extension\Core\Type\FormType }
 
   boekkooi.jquery_validation.form.button_extension:
-    class: %boekkooi.jquery_validation.form.button_extension.class%
+    class: '%boekkooi.jquery_validation.form.button_extension.class%'
     tags:
       - { name: form.type_extension, alias: button, extended_type: Symfony\Component\Form\Extension\Core\Type\ButtonType }
 
   boekkooi.jquery_validation.rule_processor:
-    class: %boekkooi.jquery_validation.rule_processor.class%
+    class: '%boekkooi.jquery_validation.rule_processor.class%'
     arguments:
       - []
 
   boekkooi.jquery_validation.rule_compiler:
-    class: %boekkooi.jquery_validation.rule_compiler.class%
+    class: '%boekkooi.jquery_validation.rule_compiler.class%'
     arguments:
       - []
 
   boekkooi.jquery_validation.constraint_finder:
-    class: %boekkooi.jquery_validation.constraint_finder.class%
+    class: '%boekkooi.jquery_validation.constraint_finder.class%'
     arguments:
       - "@validator.mapping.class_metadata_factory"
diff --git a/src/Resources/config/twig.yml b/src/Resources/config/twig.yml
index ee742a3..cb79435 100644
--- a/src/Resources/config/twig.yml
+++ b/src/Resources/config/twig.yml
@@ -3,6 +3,6 @@ parameters:
 
 services:
   boekkooi.jquery_validation.twig.jquery_validation:
-    class: %boekkooi.jquery_validation.twig.jquery_validation.class%
+    class: '%boekkooi.jquery_validation.twig.jquery_validation.class%'
     tags:
       - { name: twig.extension }