diff --git a/manifests/init.pp b/manifests/init.pp
index f462dc2..f9da415 100644
--- a/manifests/init.pp
+++ b/manifests/init.pp
@@ -68,7 +68,7 @@
   Optional[String[1]] $gem_source = undef,
   String[1] $gem_provider,
   Enum['content', 'source'] $plugin_file_transfer_type = 'source',
-  Optional[Array[String]] $gem_options,
+  Optional[Array[String]] $gem_options = [],
 ) {
   $factspath = "${configdir}/generated-facts.yaml"