diff --git a/bigchaindb/pipelines/block.py b/bigchaindb/pipelines/block.py
index 4142b234..9039938b 100644
--- a/bigchaindb/pipelines/block.py
+++ b/bigchaindb/pipelines/block.py
@@ -116,7 +116,7 @@ class BlockPipeline:
         Returns:
             :class:`~bigchaindb.models.Block`: The Block.
         """
-        logger.info('Write new block %s with %s transactions', block.id, block.transactions)
+        logger.info('Write new block %s with %s transactions', block.id, len(block.transactions))
         self.bigchain.write_block(block)
         return block