diff --git a/install_and_cache_pkgs.sh b/install_and_cache_pkgs.sh
index d402901..bbf54dc 100755
--- a/install_and_cache_pkgs.sh
+++ b/install_and_cache_pkgs.sh
@@ -44,7 +44,7 @@ manifest_filepath="$cache_dir/manifest.log"
 echo -n "Writing package manifest to $manifest_filepath..."
 manifest=
 for package in $packages; do
-  manifest=$manifest,$package:$(dpkg -s $package | grep Version | awk '{print $2}')
+  manifest=$manifest$package:$(dpkg -s $package | grep Version | awk '{print $2}'),
 done  
 # Remove trailing comma.
 echo ${manifest:0:-1} > $manifest_filepath