diff --git a/gem2rpm.yml.documentation b/gem2rpm.yml.documentation
index fbed82e..bb4893d 100644
--- a/gem2rpm.yml.documentation
+++ b/gem2rpm.yml.documentation
@@ -9,7 +9,7 @@
 # ## used by gem2rpm
 # :license: MIT or Ruby
 # ## used by gem2rpm and gem_packages
-# :version_suffix: -x_y
+# :version_suffix: '-x_y'
 # ## used by gem2rpm and gem_packages
 # :disable_docs: true
 # ## used by gem2rpm