diff --git a/build_tools/make_pkg.sh b/build_tools/make_pkg.sh
index 25a3de109..d4fcd9934 100755
--- a/build_tools/make_pkg.sh
+++ b/build_tools/make_pkg.sh
@@ -35,6 +35,6 @@ MAC_PRODUCTSIGN_ID=${MAC_PRODUCTSIGN_ID:--}
 productsign --sign "${MAC_PRODUCTSIGN_ID}" "$OUTPUT_PATH/fish-$VERSION.pkg" "$OUTPUT_PATH/fish-$VERSION-signed.pkg" && mv "$OUTPUT_PATH/fish-$VERSION-signed.pkg" "$OUTPUT_PATH/fish-$VERSION.pkg"
 
 # Make the app
-{ cd "$PKGDIR/build" && make signed_fish_macapp && zip -r "$OUTPUT_PATH/fish-$VERSION.app.zip" fish.app; }
+{ cd "$PKGDIR/build" && make -j 12 signed_fish_macapp && zip -r "$OUTPUT_PATH/fish-$VERSION.app.zip" fish.app; }
 
 rm -r "$PKGDIR"
diff --git a/build_tools/osx_package_scripts/postinstall b/build_tools/osx_package_scripts/postinstall
index 544fd1de1..e9a6a0517 100755
--- a/build_tools/osx_package_scripts/postinstall
+++ b/build_tools/osx_package_scripts/postinstall
@@ -1,3 +1,3 @@
 #!/bin/sh -x
 
-./add-shell /usr/local/bin/fish > /tmp/fish_postinstall_output.log
+./add-shell ${DSTVOLUME}usr/local/bin/fish | logger -s -t "${INSTALL_PKG_SESSION_ID}"
diff --git a/build_tools/osx_package_scripts/preinstall b/build_tools/osx_package_scripts/preinstall
new file mode 100755
index 000000000..2f2cffb3b
--- /dev/null
+++ b/build_tools/osx_package_scripts/preinstall
@@ -0,0 +1,7 @@
+#!/bin/sh -x
+
+logger -s -t "${INSTALL_PKG_SESSION_ID}" "Removing any previous installation"
+pkgutil --pkg-info ${INSTALL_PKG_SESSION_ID} && pkgutil pkgutil --only-files --files ${INSTALL_PKG_SESSION_ID} | while read installed
+     do rm -v ${DSTVOLUME}${installed}
+done | logger -s -t "${INSTALL_PKG_SESSION_ID}"
+logger -s -t "${INSTALL_PKG_SESSION_ID}" "... removed"