diff --git a/build_tools/make_pkg.sh b/build_tools/make_pkg.sh
index 44897afb6..71c8ee1ed 100755
--- a/build_tools/make_pkg.sh
+++ b/build_tools/make_pkg.sh
@@ -2,11 +2,11 @@
 
 # Script to produce an OS X installer .pkg and .app(.zip)
 
-VERSION=`git describe --always --dirty 2>/dev/null`
+VERSION=$(git describe --always --dirty 2>/dev/null)
 if test -z "$VERSION" ; then
   echo "Could not get version from git"
   if test -f version; then
-    VERSION=`cat version`
+    VERSION=$(cat version)
   fi
 fi
 
@@ -17,19 +17,19 @@ set -x
 #Exit on error
 set -e
 
-PKGDIR=`mktemp -d`
+PKGDIR=$(mktemp -d)
 
 SRC_DIR=$PWD
 OUTPUT_PATH=${FISH_ARTEFACT_PATH:-~/fish_built}
 
-mkdir -p $PKGDIR/build $PKGDIR/root $PKGDIR/intermediates $PKGDIR/dst
-( cd "$PKGDIR/build" && cmake -DCMAKE_BUILD_TYPE=RelWithDebInfo "$SRC_DIR" && make -j 4 && env DESTDIR=$PKGDIR/root/ make install )
-pkgbuild --scripts build_tools/osx_package_scripts --root $PKGDIR/root/ --identifier 'com.ridiculousfish.fish-shell-pkg' --version "$VERSION"  $PKGDIR/intermediates/fish.pkg
+mkdir -p "$PKGDIR/build" "$PKGDIR/root" "$PKGDIR/intermediates" "$PKGDIR/dst"
+{ cd "$PKGDIR/build" && cmake -DCMAKE_BUILD_TYPE=RelWithDebInfo "$SRC_DIR" && make -j 4 && env DESTDIR="$PKGDIR/root/" make install; }
+pkgbuild --scripts build_tools/osx_package_scripts --root "$PKGDIR/root/" --identifier 'com.ridiculousfish.fish-shell-pkg' --version "$VERSION" "$PKGDIR/intermediates/fish.pkg"
 
-productbuild  --package-path $PKGDIR/intermediates --distribution build_tools/osx_distribution.xml --resources build_tools/osx_package_resources/ $OUTPUT_PATH/fish-$VERSION.pkg
+productbuild  --package-path "$PKGDIR/intermediates" --distribution build_tools/osx_distribution.xml --resources build_tools/osx_package_resources/ "$OUTPUT_PATH/fish-$VERSION.pkg"
 
 
 # Make the app
-( cd "$PKGDIR/build" && make fish_macapp && zip -r "$OUTPUT_PATH/fish-$VERSION.app.zip" fish.app )
+{ cd "$PKGDIR/build" && make fish_macapp && zip -r "$OUTPUT_PATH/fish-$VERSION.app.zip" fish.app; }
 
-rm -r $PKGDIR
+rm -r "$PKGDIR"