diff --git a/phoebus-product/phoebus.sh b/phoebus-product/phoebus.sh
index c6f44d7306..0147773669 100755
--- a/phoebus-product/phoebus.sh
+++ b/phoebus-product/phoebus.sh
@@ -5,7 +5,8 @@
 # When deploying, change "TOP"
 # to the absolute installation path
 # TOP="."
-TOP="$( cd "$(dirname "$0")" ; pwd -P )"
+realpath=$(realpath "$0")
+TOP=$(dirname "$realpath")
 
 # Ideally, assert that Java is found
 # export JAVA_HOME=/opt/jdk-9
@@ -19,7 +20,7 @@ fi
 if [ -d "${TOP}/update" ]
 then
   echo "Installing update..."
-  cd ${TOP}
+  cd "${TOP}"
   rm -rf doc lib
   mv update/* .
   rmdir update
@@ -27,7 +28,7 @@ then
 fi
 
 
-JAR=`echo ${TOP}/product-*.jar`
+JAR=`echo "${TOP}"/product-*.jar`
 
 # To get one instance, use server mode
 OPT="-server 4918"
@@ -40,10 +41,10 @@ firstarg=$1;
 
 if test "${firstarg#*$filter1}" != "$firstarg"; then
   # Run MEDM converter etc. in foreground
-  java -Dfile.encoding=UTF-8 -jar $JAR $OPT "$@"
+  java -Dfile.encoding=UTF-8 -jar "$JAR" $OPT "$@"
 elif test "${firstarg#*$filter2}" != "$firstarg"; then
-    java -Dfile.encoding=UTF-8 -jar $JAR $OPT "$@"
+    java -Dfile.encoding=UTF-8 -jar "$JAR" $OPT "$@"
 else
   # Run UI as separate thread
-  java -Dfile.encoding=UTF-8 -jar $JAR $OPT "$@" &
+  java -Dfile.encoding=UTF-8 -jar "$JAR" $OPT "$@" &
 fi