diff --git a/lib/vagrant-google/config.rb b/lib/vagrant-google/config.rb
index c18e1aa..fe612de 100644
--- a/lib/vagrant-google/config.rb
+++ b/lib/vagrant-google/config.rb
@@ -210,6 +210,11 @@ def zone_config(zone, attributes=nil, &block)
         @__zone_config[zone] << block if block_given?
       end
 
+      def expand_path(path, root_path)
+        return path if not path
+        return Pathname.new(path).expand_path(root_path)
+      end
+
       #-------------------------------------------------------------------
       # Internal methods.
       #-------------------------------------------------------------------
@@ -338,6 +343,9 @@ def validate(machine)
         if @zone
           config = get_zone_config(@zone)
 
+          config.google_key_location = expand_path(config.google_key_location, machine.env.root_path)
+          config.google_json_key_location = expand_path(config.google_json_key_location, machine.env.root_path)
+
           errors << I18n.t("vagrant_google.config.google_project_id_required") if \
             config.google_project_id.nil?
           errors << I18n.t("vagrant_google.config.google_client_email_required") if \