diff --git a/docker-gc b/docker-gc
index 735d4f0..16ce95e 100755
--- a/docker-gc
+++ b/docker-gc
@@ -54,7 +54,7 @@ SYSLOG_LEVEL=${SYSLOG_LEVEL:=info}
 SYSLOG_TAG=${SYSLOG_TAG:=docker-gc}
 DRY_RUN=${DRY_RUN:=0}
 
-for pid in $(pidof -s docker-gc); do
+for pid in $(pgrep -f docker-gc); do
     if [[ $pid != $$ ]]; then
         echo "[$(date)] : docker-gc : Process is already running with PID $pid"
         exit 1