diff --git a/firmware-docker-build.sh b/firmware-docker-build.sh
index 2b32c6c7b..564a45e7e 100755
--- a/firmware-docker-build.sh
+++ b/firmware-docker-build.sh
@@ -13,11 +13,12 @@ docker run -t -v $(pwd)/output:/output $IMAGETAG /bin/sh -c "\
 	make -C vendor/libopencm3 && \
 	make && \
 	make -C firmware && \
+	make -C firmware sign && \
 	cp firmware/trezor.bin /output/trezor-$FIRMWARETAG.bin"
 
 echo "---------------------"
 echo "Firmware fingerprint:"
 FILENAME=output/trezor-$FIRMWARETAG.bin
-sha256sum "$FILENAME"
+tail -c +257 "$FILENAME" | sha256sum
 FILESIZE=$(stat -c%s "$FILENAME")
 echo "Firmware size: $FILESIZE bytes (out of 491520 maximum)"