diff --git a/mkosi.default.d/10-systemd.conf b/mkosi.default.d/10-systemd.conf
index 00363e2a9f..8efd1e97fa 100644
--- a/mkosi.default.d/10-systemd.conf
+++ b/mkosi.default.d/10-systemd.conf
@@ -13,7 +13,6 @@ OutputDirectory=mkosi.output
 [Content]
 BuildDirectory=mkosi.builddir
 Cache=mkosi.cache
-InstallDirectory=mkosi.installdir
 SourceFileTransferFinal=copy-git-others
 
 [Host]