diff --git a/defaultenv/bin/_update b/defaultenv/bin/_update
index f736acc..1bcb71c 100644
--- a/defaultenv/bin/_update
+++ b/defaultenv/bin/_update
@@ -35,16 +35,16 @@
 echo
 echo "erasing partition $part"
 echo
-erase $part
+erase $part || exit 1
 
 echo
 echo "flashing $image to $part"
 echo
 
 if [ x$mode = xtftp ]; then
-	tftp $image $part
+	tftp $image $part || exit 1
 else
-	cp $image $part
+	cp $image $part || exit 1
 fi
 
 protect $part