diff --git a/conf/nginx.conf b/conf/nginx.conf
index 31afad1..d16f443 100644
--- a/conf/nginx.conf
+++ b/conf/nginx.conf
@@ -42,7 +42,7 @@ location __PATH__/ {
 
         location ~ js/container_.*_preview\.js$ {
         expires off;
-        more_set_headers 'Cache-Control: private, no-cache, no-store';
+        more_set_headers "Cache-Control: private, no-cache, no-store";
     }
 
     location ~ \.(gif|ico|jpg|png|svg|js|css|htm|html|mp3|mp4|wav|ogg|avi|ttf|eot|woff|woff2|json)$ {
@@ -50,8 +50,8 @@ location __PATH__/ {
         ## Cache images,CSS,JS and webfonts for an hour
         ## Increasing the duration may improve the load-time, but may cause old files to show after an Matomo upgrade
         expires 1h;
-        more_set_headers 'Cache-Control: public';
-        more_set_headers 'Pragma public';
+        more_set_headers "Cache-Control: public";
+        more_set_headers "Pragma: public";
     }
 
     location __PATH__/(libs|vendor|plugins|misc|node_modules) {