diff --git a/Resources/config/services.yml b/Resources/config/services.yml
index 4d43272..259ff68 100644
--- a/Resources/config/services.yml
+++ b/Resources/config/services.yml
@@ -1,19 +1,19 @@
 services:
     # Search Engine
     iakumai.sphinxsearch.search:
-        class: %iakumai.sphinxsearch.search.class%
-        file: %iakumai.sphinxsearch.sphinx_api.file%
+        class: "%iakumai.sphinxsearch.search.class%"
+        file: "%iakumai.sphinxsearch.sphinx_api.file%"
         arguments:
-            - %iakumai.sphinxsearch.searchd.host%
-            - %iakumai.sphinxsearch.searchd.port%
-            - %iakumai.sphinxsearch.searchd.socket%
+            - "%iakumai.sphinxsearch.searchd.host%"
+            - "%iakumai.sphinxsearch.searchd.port%"
+            - "%iakumai.sphinxsearch.searchd.socket%"
         calls:
             - [setBridge, ["@iakumai.sphinxsearch.doctrine.bridge"]]
 
     # Doctrine Bridge
     iakumai.sphinxsearch.doctrine.bridge:
-        class: %iakumai.sphinxsearch.doctrine.bridge.class%
-        arguments: ["@service_container", %iakumai.sphinxsearch.doctrine.entity_manager%, %iakumai.sphinxsearch.indexes%]
+        class: "%iakumai.sphinxsearch.doctrine.bridge.class%"
+        arguments: ["@service_container", "%iakumai.sphinxsearch.doctrine.entity_manager%", "%iakumai.sphinxsearch.indexes%"]
 
     # Twig extension
     iakumai.sphinxsearch.twig.extension_0: