diff --git a/script/systemd/zammad-rails.service b/script/systemd/zammad-rails.service
index 68107b735..a92ad7a51 100644
--- a/script/systemd/zammad-rails.service
+++ b/script/systemd/zammad-rails.service
@@ -7,13 +7,13 @@ Requires=zammad.service
 
 [Service]
 EnvironmentFile=/etc/zammad/zammad.env
-User=${ZAMMAD_USER:-zammad}
-Group=${ZAMMAD_GROUP:-zammad}
+User=${ZAMMAD_USER}
+Group=${ZAMMAD_GROUP}
 Restart=always
 
-WorkingDirectory=${ZAMMAD_WORKING_DIRECTORY:-/opt/zammad}
+WorkingDirectory=${ZAMMAD_WORKING_DIRECTORY}
 
-ExecStart=/bin/bash -l -c "${BUNDLE_BINARY:-bundle} exec script/rails server -b ${ZAMMAD_BIND_IP:-127.0.0.1} -p ${ZAMMAD_RAILS_PORT:-3000}"
+ExecStart=/bin/bash -l -c "${BUNDLE_BINARY} exec script/rails server -b ${ZAMMAD_BIND_IP} -p ${ZAMMAD_RAILS_PORT}"
 
 [Install]
 WantedBy=zammad.service
diff --git a/script/systemd/zammad-scheduler.service b/script/systemd/zammad-scheduler.service
index b4a6a0e53..ec5653727 100644
--- a/script/systemd/zammad-scheduler.service
+++ b/script/systemd/zammad-scheduler.service
@@ -8,13 +8,13 @@ Requires=zammad.service
 [Service]
 Type=forking
 EnvironmentFile=/etc/zammad/zammad.env
-User=${ZAMMAD_USER:-zammad}
-Group=${ZAMMAD_GROUP:-zammad}
+User=${ZAMMAD_USER}
+Group=${ZAMMAD_GROUP}
 Restart=always
 
-WorkingDirectory=${ZAMMAD_WORKING_DIRECTORY:-/opt/zammad}
+WorkingDirectory=${ZAMMAD_WORKING_DIRECTORY}
 
-ExecStart=/bin/bash -l -c "${BUNDLE_BINARY:-bundle} exec script/scheduler.rb start"
+ExecStart=/bin/bash -l -c "${BUNDLE_BINARY} exec script/scheduler.rb start"
 
 [Install]
 WantedBy=zammad.service
diff --git a/script/systemd/zammad-websocket.service b/script/systemd/zammad-websocket.service
index d022e78d4..8c1450e66 100644
--- a/script/systemd/zammad-websocket.service
+++ b/script/systemd/zammad-websocket.service
@@ -7,13 +7,13 @@ Requires=zammad.service
 
 [Service]
 EnvironmentFile=/etc/zammad/zammad.env
-User=${ZAMMAD_USER:-zammad}
-Group=${ZAMMAD_GROUP:-zammad}
+User=${ZAMMAD_USER}
+Group=${ZAMMAD_GROUP}
 Restart=always
 
-WorkingDirectory=${ZAMMAD_WORKING_DIRECTORY:-/opt/zammad}
+WorkingDirectory=${ZAMMAD_WORKING_DIRECTORY}
 
-ExecStart=/bin/bash -l -c "${BUNDLE_BINARY:-bundle} exec script/websocket-server.rb -b ${ZAMMAD_BIND_IP:-127.0.0.1} -p ${ZAMMAD_WEBSOCKET_PORT:-6042} start"
+ExecStart=/bin/bash -l -c "${BUNDLE_BINARY} exec script/websocket-server.rb -b ${ZAMMAD_BIND_IP} -p ${ZAMMAD_WEBSOCKET_PORT} start"
 
 [Install]
 WantedBy=zammad.service
diff --git a/script/systemd/zammad.service b/script/systemd/zammad.service
index 46e4a2b8f..6fb380e1f 100644
--- a/script/systemd/zammad.service
+++ b/script/systemd/zammad.service
@@ -9,8 +9,8 @@ Wants=zammad-websocket.service
 
 [Service]
 EnvironmentFile=/etc/zammad/zammad.env
-User=${ZAMMAD_USER:-zammad}
-Group=${ZAMMAD_GROUP:-zammad}
+User=${ZAMMAD_USER}
+Group=${ZAMMAD_GROUP}
 Restart=always
 ExecStart=/bin/sleep infinity