diff --git a/lib/docs/main.js b/lib/docs/main.js
index ad7dab91fb..cbe0a60057 100644
--- a/lib/docs/main.js
+++ b/lib/docs/main.js
@@ -811,7 +811,10 @@ Happy writing!
 
     let fnNode = getAstNode(fnDecl.src);
     let fields = fnNode.fields;
-    let isVarArgs = fnNode.varArgs;
+    if (fields === null) {
+      fields = getAstNode(typeObj.src).fields;
+    }
+    let isVarArgs = typeObj.is_var_args;
 
     for (let i = 0; i < fields.length; i += 1) {
       let field = fields[i];