diff --git a/System-configuration.md b/System-configuration.md
index 02e9345..27618c0 100644
--- a/System-configuration.md
+++ b/System-configuration.md
@@ -436,7 +436,7 @@ in italics.
 
 ### Example configuration file
 
-```{.yml}
+```{.ini}
 NODE_ENV=production
 API_BASE=https://recodex.projekty.ms.mff.cuni.cz:4000/v1
 PORT=8080