diff --git a/cardano-node/src/Cardano/Node/Run.hs b/cardano-node/src/Cardano/Node/Run.hs
index 6a3ed22f5b9..f53dc3069fe 100644
--- a/cardano-node/src/Cardano/Node/Run.hs
+++ b/cardano-node/src/Cardano/Node/Run.hs
@@ -287,4 +287,8 @@ handleSimpleNode p trace nodeTracers nCli nc = do
              _               -> IsNotProducer
 
     increaseMempoolCapacity :: NK.NodeArgs IO peer blk -> NK.NodeArgs IO peer blk
-    increaseMempoolCapacity args = args { NK.mempoolCap = MempoolCapacityBytes (16000000 :: Word32) }
+    increaseMempoolCapacity args =
+      args
+        { NK.maxBlockSize = NK.MaxBlockSize (20000000 :: Word32)
+        , NK.mempoolCap = MempoolCapacityBytes (16000000 :: Word32)
+        }