diff --git a/libbonobo.install b/libbonobo.install
index 5cc04eb..a48a9af 100644
--- a/libbonobo.install
+++ b/libbonobo.install
@@ -1,6 +1,6 @@
 post_upgrade() {
   ldconfig -r .
-  PID=`pidof bonobo-activation-server`
+  PID=$(pgrep '^bonobo-activation-server$')
   if [ ! -z "${PID}" ]; then
     killall -HUP bonobo-activation-server 2>&1
   fi