diff --git a/ouroboros-network/src/Ouroboros/Network/TxSubmission/Outbound.hs b/ouroboros-network/src/Ouroboros/Network/TxSubmission/Outbound.hs
index 436a8e5b25a..de53bff3160 100644
--- a/ouroboros-network/src/Ouroboros/Network/TxSubmission/Outbound.hs
+++ b/ouroboros-network/src/Ouroboros/Network/TxSubmission/Outbound.hs
@@ -9,6 +9,7 @@ module Ouroboros.Network.TxSubmission.Outbound (
     TxSubmissionMempoolReader(..),
     TraceTxSubmissionOutbound(..),
     TxSubmissionProtocolError(..),
+    MempoolSnapshot(..),
   ) where
 
 import           Data.Word (Word16)