diff --git a/chromeos_version.sh b/chromeos_version.sh
index fcebafb516..649898719e 100755
--- a/chromeos_version.sh
+++ b/chromeos_version.sh
@@ -84,9 +84,8 @@ export CHROMEOS_VERSION_STRING=\
 # Set CHROME values (Used for releases) to pass to chromeos-chrome-bin ebuild
 # URL to chrome archive
 export CHROME_BASE=
-# directory containing chrome-chromeos.zip - an svn rev or a full version
-export CHROME_BUILD=
-export CHROME_VERSION="$CHROME_BUILD"
+# export CHROME_VERSION from incoming value or NULL and let ebuild default
+export CHROME_VERSION="$CHROME_VERSION"
 
 # Print (and remember) version info.
 echo "ChromeOS version information:"