diff --git a/set_version.sh b/set_version.sh
index 6a0e961..fdf7ba4 100755
--- a/set_version.sh
+++ b/set_version.sh
@@ -1,7 +1,10 @@
 #!/bin/bash
+#
+# Called by jenkins to update version.rs with the current build number
+#
 
 if [[ -z "${BUILD_NUMBER}" ]] ; then
   echo "No BUILD_NUMBER environment variable was set"
   exit 1
 fi
-sed -i "s/.DEV_BUILD/.${BUILD_NUMBER}/" src/version.rs
+sed -i "s/.DEV_BUILD/\.${BUILD_NUMBER}/" src/version.rs