diff --git a/nixos/modules/services/misc/taskserver/default.nix b/nixos/modules/services/misc/taskserver/default.nix
index 07dbee69db0c..8a57277fafe7 100644
--- a/nixos/modules/services/misc/taskserver/default.nix
+++ b/nixos/modules/services/misc/taskserver/default.nix
@@ -411,7 +411,7 @@ in {
         } else {
           cert = "${cfg.pki.manual.server.cert}";
           key = "${cfg.pki.manual.server.key}";
-          crl = "${cfg.pki.manual.server.crl}";
+          ${mapNullable (_: "crl") cfg.pki.manual.server.crl} = "${cfg.pki.manual.server.crl}";
         });
 
         ca.cert = if needToCreateCA then "${cfg.dataDir}/keys/ca.cert"