diff --git a/bin/device-install.sh b/bin/device-install.sh
index 2904f1e0d..ca60740ab 100755
--- a/bin/device-install.sh
+++ b/bin/device-install.sh
@@ -45,7 +45,7 @@ shift "$((OPTIND-1))"
     shift
 }
 
-if [ -f "${FILENAME}" ] && [ "${FILENAME##*"update"*}" == "$FILENAME" ]; then
+if [ -f "${FILENAME}" ] && [ ! -z "${FILENAME##*"update"*}" ]; then
 	echo "Trying to flash ${FILENAME}, but first erasing and writing system information"
 	"$PYTHON" -m esptool  erase_flash
 	"$PYTHON" -m esptool  write_flash 0x00 ${FILENAME}
diff --git a/bin/device-update.sh b/bin/device-update.sh
index 47ac8595f..7233f61f6 100755
--- a/bin/device-update.sh
+++ b/bin/device-update.sh
@@ -43,7 +43,7 @@ shift "$((OPTIND-1))"
     shift
 }
 
-if [ -f "${FILENAME}" ] && [ "${FILENAME##*"update"*}" != "$FILENAME" ]; then
+if [ -f "${FILENAME}" ] && [ -z "${FILENAME##*"update"*}" ]; then
 	printf "Trying to flash update ${FILENAME}"
 	$PYTHON -m esptool --baud 115200 write_flash 0x10000 ${FILENAME}
 else