diff --git a/libexec/rbenv-init b/libexec/rbenv-init
index 1661a052..855e9a58 100755
--- a/libexec/rbenv-init
+++ b/libexec/rbenv-init
@@ -138,7 +138,7 @@ esac
 if [ "$shell" != "fish" ]; then
 IFS="|"
 cat <<EOS
-  command="\$1"
+  command="\${1:-}"
   if [ "\$#" -gt 0 ]; then
     shift
   fi