diff --git a/typeahead/typeahead.d.ts b/typeahead/typeahead.d.ts
index 159caaacdd..7317aa4c79 100644
--- a/typeahead/typeahead.d.ts
+++ b/typeahead/typeahead.d.ts
@@ -119,8 +119,8 @@ declare module Twitter.Typeahead {
          * For a given suggestion object, determines the string representation of it.
          * This will be used when setting the value of the input control after a suggestion is selected. Can be either a key string or a function that transforms a suggestion object into a string.
          * Defaults to value.
-          */
-        displayKey?: string;
+         */
+        displayKey?: string | ((obj: any) => string);
 
         /**
          * A hash of templates to be used when rendering the dataset.