diff --git a/src/usbinstall.sh b/src/usbinstall.sh
index 113c656..e2f2c13 100755
--- a/src/usbinstall.sh
+++ b/src/usbinstall.sh
@@ -65,7 +65,7 @@ function dbus_properties_get_bool() {
 # Arg 1: value%
 set_pbar()
 {
-	if [ $DBUS_USBINSTALL == 1 ]; then
+	if [ "$DBUS_USBINSTALL" == "1" ]; then
 		dbus-send --print-reply --session --dest=org.openmamba.usbinstall /org/openmamba/usbinstall org.openmamba.usbinstall.Set_progressBar int32:$1
 	fi
 }
@@ -74,7 +74,7 @@ set_pbar()
 # Arg 1: string
 set_status()
 {
-	if [ $DBUS_USBINSTALL == 1 ]; then
+	if [ "$DBUS_USBINSTALL" == "1" ]; then
 		dbus-send --print-reply --session --dest=org.openmamba.usbinstall /org/openmamba/usbinstall org.openmamba.usbinstall.Set_description "string:$1"
 	fi
 }