diff --git a/bin/exec-env b/bin/exec-env
index 9f229d5..8958eeb 100755
--- a/bin/exec-env
+++ b/bin/exec-env
@@ -3,6 +3,7 @@
 current_script_path=${BASH_SOURCE[0]}
 ruby_plugin_dir=$(dirname "$(dirname "$current_script_path")")
 
+RUBYLIB=${RUBYLIB:-}
 if [ "$RUBYLIB" = "" ]; then
   export RUBYLIB="$ruby_plugin_dir/rubygems-plugin"
 else