diff --git a/systemd/start-eddn-service b/systemd/start-eddn-service
index 0b5ef8d..c3d0d11 100755
--- a/systemd/start-eddn-service
+++ b/systemd/start-eddn-service
@@ -79,7 +79,7 @@ then
   
   if [ -f "${LOG_DIR}/${SERVICE}.pid" ];
   then
-    if ps -C python $(cat "${LOG_DIR}/${SERVICE}.pid") > /dev/null 2>&1;
+    if ps -C python -p $(cat "${LOG_DIR}/${SERVICE}.pid") > /dev/null 2>&1;
     then
       echo "${SERVICE}: already running as PID $(cat "${LOG_DIR}/${SERVICE}.pid")" >&2
       exit ${EXIT_SERVICE_ALREADY_RUNNING}
@@ -105,7 +105,7 @@ else
     # We need to ensure there isn't already one, via the .pid file
     if [ -f "${LOG_DIR}/${SERVICE}.pid" ];
     then
-      if ps -C python $(cat "${LOG_DIR}/${SERVICE}.pid") > /dev/null 2>&1;
+      if ps -C python -p $(cat "${LOG_DIR}/${SERVICE}.pid") > /dev/null 2>&1;
       then
         echo "${SERVICE}: already running as PID $(cat "${LOG_DIR}/${SERVICE}.pid")" >&2
         exit ${EXIT_SERVICE_ALREADY_RUNNING}