diff --git a/plugins/pyenv-binary/libexec/pyenv-binary-save b/plugins/pyenv-binary/libexec/pyenv-binary-save
index 32df661b..4b1047a3 100755
--- a/plugins/pyenv-binary/libexec/pyenv-binary-save
+++ b/plugins/pyenv-binary/libexec/pyenv-binary-save
@@ -63,7 +63,7 @@ case "$version" in
 esac
 
 case "$package_name" in
-*/* | .. | . )
+*/* | .. | . | *[[:cntrl:]]* )
   echo "pyenv-binary: invalid package name \`${package_name}'" >&2
   exit 1
   ;;