diff --git a/mkosi.conf b/mkosi.conf
index 9961407a04..5e941959e5 100644
--- a/mkosi.conf
+++ b/mkosi.conf
@@ -4,7 +4,7 @@
 Images=system
 
 [Output]
-OutputDirectory=mkosi.output
+@OutputDirectory=mkosi.output
 BuildDirectory=mkosi.builddir
 CacheDirectory=mkosi.cache