diff --git a/classes/sdcard_image-rpi.bbclass b/classes/sdcard_image-rpi.bbclass
index 6960aca..57cefea 100644
--- a/classes/sdcard_image-rpi.bbclass
+++ b/classes/sdcard_image-rpi.bbclass
@@ -72,8 +72,8 @@ SDIMG = "${DEPLOY_DIR_IMAGE}/${IMAGE_NAME}.rootfs.rpi-sdimg"
 FATPAYLOAD ?= ""
 
 IMAGEDATESTAMP = "${@time.strftime('%Y.%m.%d',time.gmtime())}"
-IMAGE_CMD_rpi-sdimg[vardepsexclude] = "IMAGEDATESTAMP"
-IMAGE_CMD_rpi-sdimg[vardepsexclude] = "DATETIME"
+IMAGE_CMD_rpi-sdimg[vardepsexclude] += "IMAGEDATESTAMP"
+IMAGE_CMD_rpi-sdimg[vardepsexclude] += "DATETIME"
 
 IMAGE_CMD_rpi-sdimg () {