diff --git a/Makefile b/Makefile
index 2759704b0f2251f053861f14013a95be24145d6a..54fdf331fd4c5adabff14606a219331ecbed7e0e 100644
--- a/Makefile
+++ b/Makefile
@@ -98,7 +98,7 @@ lib/%.a: $(PKGFILES)
 	@XBUILD=no ./gui/build.sh --just-golib
 
 relink_vendor:
-	@echo "==========RELINK VENDOR=========="
+	@echo "============RELINK VENDOR============="
 	@echo "PLATFORM: ${PLATFORM}"
 	@echo "VENDOR_PATH: ${VENDOR_PATH}"
 	@echo "PROVIDER: ${PROVIDER}"
@@ -114,28 +114,28 @@ ifeq ($(VENDOR_PATH), providers)
 	@ln -s ${PROVIDER}/assets providers/assets
 endif
 endif
-	@echo "==========RELINK VENDOR=========="
+	@echo "============RELINK VENDOR============="
 
 build_golib: lib/libgoshim.a
 
 build_gui: relink_vendor
-	@echo "==========BUILD GUI=========="
+	@echo "==============BUILD GUI==============="
 	@echo "TARGET: ${TARGET}"
 	@echo "VENDOR_PATH: ${VENDOR_PATH}"
 	@XBUILD=no TARGET=${TARGET} VENDOR_PATH=${VENDOR_PATH} gui/build.sh --skip-golib
-	@echo "==========BUILD GUI=========="
+	@echo "============BUILD GUI================="
 
 build: build_golib build_helper build_gui
 
 build_helper:
-	@echo "==========BUILDER HELPER=========="
+	@echo "=============BUILDER HELPER==========="
 	@echo "PLATFORM: ${PLATFORM}"
 	@echo "APPNAME: ${APPNAME}"
 	@echo "VERSION: ${VERSION}"
 	@echo "EXTRA_GO_LDFLAGS: ${EXTRA_GO_LDFLAGS}"
 	@mkdir -p build/bin/${PLATFORM}
 	@go build -o build/bin/${PLATFORM}/bitmask-helper -ldflags "-X main.AppName=${APPNAME} -X main.Version=${VERSION} ${EXTRA_GO_LDFLAGS}" ./cmd/bitmask-helper/
-	@echo "==========BUILDER HELPER=========="
+	@echo "===========BUILDER HELPER============="
 
 build_openvpn:
 	@[ -f $(OPENVPN_BIN) ] && echo "OpenVPN already built at" $(OPENVPN_BIN) || ./branding/thirdparty/openvpn/build_openvpn.sh
diff --git a/branding/templates/qtinstaller/osx-data/uninstall.py b/branding/templates/qtinstaller/osx-data/uninstall.py
index 7aa8a563674b4ee47f3cd41f071d461d13f1aa08..7520321a9840b1a473dc993eeb2e62f1ad017304 100755
--- a/branding/templates/qtinstaller/osx-data/uninstall.py
+++ b/branding/templates/qtinstaller/osx-data/uninstall.py
@@ -12,8 +12,9 @@ HELPER_PLIST = "/Library/LaunchDaemons/se.leap.bitmask-helper.plist"
 
 _dir = os.path.dirname(os.path.realpath(__file__))
 
-def main():
-    log = open(os.path.join('/tmp', 'bitmask-uninstall.log'), 'w')
+def main(stage="uninstall"):
+    logfile = "bitmask-{stage}.log".format(stage=stage)
+    log = open(os.path.join('/tmp', logfile), 'w')
     log.write('Checking for admin privileges...\n')
 
     _id = os.getuid()
@@ -37,7 +38,7 @@ def main():
     log.write("result: %s \n" % str(out))
     
     # all done
-    log.write('uninstall script: done\n')
+    log.write(stage + ' script: done\n')
     sys.exit(0)
 
 
@@ -67,4 +68,7 @@ def _getProcessList():
     return _out
 
 if __name__ == "__main__":
-    main()
+    stage="uninstall"
+    if len(sys.argv) > 2 and sys.argv[2] == "pre":
+        stage="pre-install"
+    main(stage)
diff --git a/branding/templates/qtinstaller/packages/bitmaskvpn/meta/install.js b/branding/templates/qtinstaller/packages/bitmaskvpn/meta/install.js
index 0b065d674f6bd56c0d8aa2c278015a5e1dbaf418..407ea395217556631a2bb12f7156a5e4d2b37d3c 100644
--- a/branding/templates/qtinstaller/packages/bitmaskvpn/meta/install.js
+++ b/branding/templates/qtinstaller/packages/bitmaskvpn/meta/install.js
@@ -70,6 +70,7 @@ Component.prototype.createOperations = function ()
     if (systemInfo.productType === "windows") {
         postInstallWindows();
     } else if (systemInfo.productType === "osx") {
+        preInstallOSX();
         postInstallOSX();
     } else {
         postInstallLinux();
@@ -91,6 +92,7 @@ Component.prototype.installationFinished = function()
 }
 
 function postInstallWindows() {
+    // TODO - check if we're on Windows10 or older, and use the needed tap-windows installer accordingly.
     console.log("Installing OpenVPN tap driver");
     component.addElevatedOperation("Execute", "@TargetDir@/tap-windows.exe", "/S", "/SELECT_UTILITIES=1");  /* TODO uninstall? */
     console.log("Now trying to install our helper");
@@ -108,6 +110,16 @@ function postInstallWindows() {
     );
 }
 
+function preInstallOSX() {
+    console.log("Pre-installation for OSX");
+    // TODO use installer filepath??
+    component.addElevatedOperation(
+	"Execute", "{0}",
+   	"@TargetDir@/uninstall.py", "pre",
+	"errormessage=There was an error during the pre-installation script, things might be broken. Please report this error and attach the pre-install.log file."
+    );
+}
+
 function postInstallOSX() {
     console.log("Post-installation for OSX");
     component.addElevatedOperation(