diff --git a/site/_docs/configuration.md b/site/_docs/configuration.md
index 1b1b707c..a12b2e26 100644
--- a/site/_docs/configuration.md
+++ b/site/_docs/configuration.md
@@ -397,7 +397,7 @@ webrick:
 
 ### Defaults
 
-We only provide on default and that's a Content-Type header that disables
+We only provide one default and that's a Content-Type header that disables
 caching in development so that you don't have to fight with Chrome's aggressive
 caching when you are in development mode.