diff --git a/docker.nix b/docker.nix
index 0e29d0e0b..251bd2f46 100644
--- a/docker.nix
+++ b/docker.nix
@@ -201,7 +201,7 @@ let
 
       mkdir $out/tmp
 
-      mkdir $out/var/tmp
+      mkdir -p $out/var/tmp
 
       mkdir -p $out/etc/nix
       cat $nixConfContentsPath > $out/etc/nix/nix.conf