diff --git a/dev-docs/publisher-api-reference.md b/dev-docs/publisher-api-reference.md
index 0473084926..989971d08a 100644
--- a/dev-docs/publisher-api-reference.md
+++ b/dev-docs/publisher-api-reference.md
@@ -416,7 +416,7 @@ Request bids. When `adUnits` or `adUnitCodes` are not specified, request bids fo
 | requestObj.adUnitCodes | Optional | `Array of strings` | adUnit codes to request. Use this or `requestObj.adUnits`. Default to all `adUnitCodes` if empty. |
 | requestObj.adUnits | Optional | `Array of objects` | AdUnitObjects to request. Use this or `requestObj.adUnitCodes`. Default to all `adUnits` if empty. |
 | requestObj.timeout | Optional | `Integer` | Timeout for requesting the bids specified in milliseconds |
-| requestObj.bidsBackHandler | Optional | `function` | Callback to execute when all the bid responses are back or the timeout hits. |
+| requestObj.bidsBackHandler | Optional | `function` | Callback to execute when all the bid responses are back or the timeout hits. Callback will be passed two parameters, the bids themselves and `timedOut`, which will be true if any bidders timed out. |
 | requestObj.labels | Optional | `Array of strings` | Defines [labels](#labels) that may be matched on ad unit targeting conditions. |
 
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