diff --git a/etc/kaleidoscope-builder.conf b/etc/kaleidoscope-builder.conf
index bb34669a..32a417e0 100644
--- a/etc/kaleidoscope-builder.conf
+++ b/etc/kaleidoscope-builder.conf
@@ -125,7 +125,7 @@ if [ "${uname_S}" = "Darwin" ]; then
     find_device_port() {
 	DIR=$(dirname "$0")
 	DEVICE_PORT_PROBER="${DIR}/find-device-port-macos"
-	DEVICE_PORT="$(perl ${DEVICE_PORT_PROBER})"
+        DEVICE_PORT="$(perl ${DEVICE_PORT_PROBER} ${VID} ${SKETCH_PID})"
     }
 
     reset_device_cmd() {
@@ -139,9 +139,15 @@ if [ "${uname_S}" = "Darwin" ]; then
     MD5="md5"
 
     find_bootloader_ports() {
+        find_device_vid_pid
 	DIR=$(dirname "$0")
+        BOOTLOADER_VID="${BOOTLOADER_VID:-${VID}}"
 	DEVICE_PORT_PROBER="${DIR}/find-device-port-macos"
-	DEVICE_PORT_BOOTLOADER="$(perl ${DEVICE_PORT_PROBER})"
+        if [[ "${DEVICE_PORT_BOOTLOADER}" = "" ]]; then
+          DEVICE_PORT_BOOTLOADER="$(perl ${DEVICE_PORT_PROBER} ${BOOTLOADER_VID} ${BOOTLOADER_PID})"
+        else
+          echo "DEVICE_PORT_BOOTLOADER=\"${DEVICE_PORT_BOOTLOADER}\" predefined."
+        fi
     }
 
 elif [ "${uname_S}" = "FreeBSD" ]; then