diff --git a/src/Makefile b/src/Makefile
index 48f2a03..6657635 100644
--- a/src/Makefile
+++ b/src/Makefile
@@ -32,7 +32,7 @@ load: boot.bin
 .PHONY: clean depend load boot.crc.bin
 
 boot.crc.bin: boot.bin
-	IMAGES_DIR=$(IMGDIR) ./append_crc_len.sh
+	IMAGES_DIR=$(IMAGES_DIR) ./append_crc_len.sh
 
 depend:
 	makedepend -Y -- $(CFLAGS) -- *.c
diff --git a/src/append_crc_len.sh b/src/append_crc_len.sh
index ff4a8dd..c462bc4 100755
--- a/src/append_crc_len.sh
+++ b/src/append_crc_len.sh
@@ -1,6 +1,7 @@
 #!/bin/bash
 
-BOOT_CRC_BIN="boot.crc.bin"
+REV=$(git log | head -n 1 | cut -b8-14)
+BOOT_CRC_BIN="boot.crc.${REV}.bin"
 
 CRC_LEN_TMP=`mktemp`
 BOOT_BIN_TMP=`mktemp`
@@ -70,5 +71,5 @@ do
     fi
 done
 
-echo "boot.crc.bin created"
+echo "${BOOT_CRC_BIN} created"
 exit 0