diff --git a/.gitignore b/.gitignore
index 6591d5f..0d53a9f 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,3 +1,4 @@
 .DS_Store
 */.DS_Store
-data/
\ No newline at end of file
+data/
+*.txt
\ No newline at end of file
diff --git a/update-docker.sh b/update-docker.sh
index 4bc2eef..a6b3ae3 100755
--- a/update-docker.sh
+++ b/update-docker.sh
@@ -5,6 +5,10 @@
 
 date
 
+# backup container version
+date >> docker-image-versions.txt
+docker images >> docker-image-versions.txt
+
 # Create a database backup before updating.
 echo "Creating database backup..."
 ./backup.sh