diff --git a/fixtures/attribute-behavior/README.md b/fixtures/attribute-behavior/README.md
index 3c28bdd53ec4f..d14c5e55cdbd5 100644
--- a/fixtures/attribute-behavior/README.md
+++ b/fixtures/attribute-behavior/README.md
@@ -20,7 +20,7 @@ The left box shows the property (or attribute) assigned by React 15.\*, and the
 right box shows the property (or attribute) assigned by the latest version of
 React 16.
 
-Right now we use a purple outline to call out cases where the assigned property
+Right now, we use a purple outline to call out cases where the assigned property
 (or attribute) has changed between React 15 and 16.
 
 ---