diff --git a/modules/services/lieer.nix b/modules/services/lieer.nix
index 571e2af75..71f0a66e5 100644
--- a/modules/services/lieer.nix
+++ b/modules/services/lieer.nix
@@ -26,6 +26,8 @@ let
         Type = "oneshot";
         ExecStart = "${pkgs.gmailieer}/bin/gmi sync";
         WorkingDirectory = account.maildir.absPath;
+        Environment =
+          "NOTMUCH_CONFIG=${config.xdg.configHome}/notmuch/notmuchrc";
       };
     };
   };
diff --git a/tests/modules/services/lieer/lieer-service-expected.service b/tests/modules/services/lieer/lieer-service-expected.service
index 1110e85c4..8437b9895 100644
--- a/tests/modules/services/lieer/lieer-service-expected.service
+++ b/tests/modules/services/lieer/lieer-service-expected.service
@@ -1,4 +1,5 @@
 [Service]
+Environment=NOTMUCH_CONFIG=/home/hm-user/.config/notmuch/notmuchrc
 ExecStart=@lieer@/bin/gmi sync
 Type=oneshot
 WorkingDirectory=/home/hm-user/Mail/hm@example.com