diff --git a/labrador_bootstrap_pi b/labrador_bootstrap_pi
index f4503f7e..49721ddb 100755
--- a/labrador_bootstrap_pi
+++ b/labrador_bootstrap_pi
@@ -3,10 +3,12 @@
 set -e
 
 # Install prerequisites
-QT5_NOT_INSTALLED=$(dpkg -s qt5-default)
-LIBUSB_NOT_INSTALLED=$(dpkg -s libusb-1.0-0-dev)
+dpkg -s qt5-default
+QT5_NOT_INSTALLED=$?
+dpkg -s libusb-1.0-0-dev
+LIBUSB_NOT_INSTALLED=$?
 
-if [ $QT5_NOT_INSTALLED ] || [ $LIBUSB_NOT_INSTALLED ]; then
+if [ $QT5_NOT_INSTALLED != 0 ] || [ $LIBUSB_NOT_INSTALLED != 0 ]; then
     sudo apt-get update
     sudo apt-get install qt5-default
     sudo apt-get install libusb-1.0-0-dev