diff --git a/UPGRADE.md b/UPGRADE.md
index 504367f234..a206d37fab 100644
--- a/UPGRADE.md
+++ b/UPGRADE.md
@@ -79,7 +79,7 @@ a link cannot be generated):
 
     framework:
         router:
-            strict_requirements: %kernel.debug%
+            strict_requirements: "%kernel.debug%"
 
 You can even disable the requirements check on production with `null` as you should
 know that the parameters for URL generation always pass the requirements, e.g. by
@@ -90,7 +90,7 @@ The `default_locale` parameter is now a setting of the main `framework`
 configuration (it was under the `framework.session` in 2.0):
 
     framework:
-        default_locale: %locale%
+        default_locale: "%locale%"
 
 The `auto_start` setting under `framework.session` must be removed as it is
 not used anymore (the session is now always started on-demand). If
diff --git a/app/config/config.yml b/app/config/config.yml
index 5490b59079..fe0077c1a9 100644
--- a/app/config/config.yml
+++ b/app/config/config.yml
@@ -4,8 +4,8 @@ imports:
 
 framework:
     #esi:             ~
-    #translator:      { fallback: %locale% }
-    secret:          %secret%
+    #translator:      { fallback: "%locale%" }
+    secret:          "%secret%"
     router:
         resource: "%kernel.root_dir%/config/routing.yml"
         strict_requirements: ~
@@ -23,44 +23,44 @@ framework:
 
 # Twig Configuration
 twig:
-    debug:            %kernel.debug%
-    strict_variables: %kernel.debug%
+    debug:            "%kernel.debug%"
+    strict_variables: "%kernel.debug%"
 
 # Assetic Configuration
 assetic:
-    debug:          %kernel.debug%
+    debug:          "%kernel.debug%"
     use_controller: false
     bundles:        [ ]
     #java: /usr/bin/java
     filters:
         cssrewrite: ~
         #closure:
-        #    jar: %kernel.root_dir%/Resources/java/compiler.jar
+        #    jar: "%kernel.root_dir%/Resources/java/compiler.jar"
         #yui_css:
-        #    jar: %kernel.root_dir%/Resources/java/yuicompressor-2.4.7.jar
+        #    jar: "%kernel.root_dir%/Resources/java/yuicompressor-2.4.7.jar"
 
 # Doctrine Configuration
 doctrine:
     dbal:
-        driver:   %database_driver%
-        host:     %database_host%
-        port:     %database_port%
-        dbname:   %database_name%
-        user:     %database_user%
-        password: %database_password%
+        driver:   "%database_driver%"
+        host:     "%database_host%"
+        port:     "%database_port%"
+        dbname:   "%database_name%"
+        user:     "%database_user%"
+        password: "%database_password%"
         charset:  UTF8
         # if using pdo_sqlite as your database driver, add the path in parameters.yml
-        # e.g. database_path: %kernel.root_dir%/data/data.db3
-        # path:     %database_path%
+        # e.g. database_path: "%kernel.root_dir%/data/data.db3"
+        # path:     "%database_path%"
 
     orm:
-        auto_generate_proxy_classes: %kernel.debug%
+        auto_generate_proxy_classes: "%kernel.debug%"
         auto_mapping: true
 
 # Swiftmailer Configuration
 swiftmailer:
-    transport: %mailer_transport%
-    host:      %mailer_host%
-    username:  %mailer_user%
-    password:  %mailer_password%
+    transport: "%mailer_transport%"
+    host:      "%mailer_host%"
+    username:  "%mailer_user%"
+    password:  "%mailer_password%"
     spool:     { type: memory }
diff --git a/app/config/config_dev.yml b/app/config/config_dev.yml
index efcacdd43b..914c34ae22 100644
--- a/app/config/config_dev.yml
+++ b/app/config/config_dev.yml
@@ -15,7 +15,7 @@ monolog:
     handlers:
         main:
             type:   stream
-            path:   %kernel.logs_dir%/%kernel.environment%.log
+            path:   "%kernel.logs_dir%/%kernel.environment%.log"
             level:  debug
         console:
             type:   console
diff --git a/app/config/config_prod.yml b/app/config/config_prod.yml
index ceba8197cb..342837a031 100644
--- a/app/config/config_prod.yml
+++ b/app/config/config_prod.yml
@@ -19,7 +19,7 @@ monolog:
             handler:      nested
         nested:
             type:  stream
-            path:  %kernel.logs_dir%/%kernel.environment%.log
+            path:  "%kernel.logs_dir%/%kernel.environment%.log"
             level: debug
         console:
             type:  console