diff --git a/mkosi.conf.d/20-build.conf b/mkosi.conf.d/20-build.conf
index f9b4a0aaf57..83bc23e82c5 100644
--- a/mkosi.conf.d/20-build.conf
+++ b/mkosi.conf.d/20-build.conf
@@ -7,4 +7,6 @@ Environment=!NO_BUILD=1
 
 [Config]
 Dependencies=build
+
+[Build]
 BuildSourcesEphemeral=yes