diff --git a/hydra-module.nix b/hydra-module.nix
index b58be922..8e02dcbb 100644
--- a/hydra-module.nix
+++ b/hydra-module.nix
@@ -272,12 +272,12 @@ in
           ln -sf ${hydraConf} ${baseDir}/hydra.conf
 
           mkdir -m 0700 -p ${baseDir}/www
-          chown hydra-www.hydra ${baseDir}/www
+          chown hydra-www:hydra ${baseDir}/www
 
           mkdir -m 0700 -p ${baseDir}/queue-runner
           mkdir -m 0750 -p ${baseDir}/build-logs
           mkdir -m 0750 -p ${baseDir}/runcommand-logs
-          chown hydra-queue-runner.hydra \
+          chown hydra-queue-runner:hydra \
             ${baseDir}/queue-runner \
             ${baseDir}/build-logs \
             ${baseDir}/runcommand-logs
@@ -308,7 +308,7 @@ in
             rmdir /nix/var/nix/gcroots/per-user/hydra-www/hydra-roots
           fi
 
-          chown hydra.hydra ${cfg.gcRootsDir}
+          chown hydra:hydra ${cfg.gcRootsDir}
           chmod 2775 ${cfg.gcRootsDir}
         '';
         serviceConfig.ExecStart = "${cfg.package}/bin/hydra-init";