diff --git a/lib/main/build-doc.js b/lib/main/build-doc.js
index e4057260e..97569549c 100644
--- a/lib/main/build-doc.js
+++ b/lib/main/build-doc.js
@@ -33,8 +33,13 @@ var config = {
 };
 
 function postprocess(string) {
-  // Fix docdown bug by wrapping symbol property identifiers in brackets.
-  return string.replace(/\.(Symbol\.(?:[a-z]+[A-Z]?)+)/g, '[$1]');
+  // Fix docdown bugs.
+  return string
+    // Repair the default value of `chars`.
+    // See https://github.com/eslint/doctrine/issues/157 for more details.
+    .replace(/\bchars=''/g, "chars=' '")
+    // Wrap symbol property identifiers in brackets.
+    .replace(/\.(Symbol\.(?:[a-z]+[A-Z]?)+)/g, '[$1]');
 }
 
 /*----------------------------------------------------------------------------*/