diff --git a/libethcore/BlockInfo.cpp b/libethcore/BlockInfo.cpp
index f04353aac..bbd78224f 100644
--- a/libethcore/BlockInfo.cpp
+++ b/libethcore/BlockInfo.cpp
@@ -104,6 +104,8 @@ void BlockInfo::populateFromHeader(RLP const& _header, Strictness _s)
 	int field = 0;
 	try
 	{
+		if (_header.itemCount() != 15)
+			throw InvalidBlockHeaderItemCount();
 		parentHash = _header[field = 0].toHash<h256>(RLP::VeryStrict);
 		sha3Uncles = _header[field = 1].toHash<h256>(RLP::VeryStrict);
 		coinbaseAddress = _header[field = 2].toHash<Address>(RLP::VeryStrict);
diff --git a/libethcore/Exceptions.h b/libethcore/Exceptions.h
index 0059854f7..f9eab7c8d 100644
--- a/libethcore/Exceptions.h
+++ b/libethcore/Exceptions.h
@@ -67,6 +67,7 @@ struct InvalidReceiptsStateRoot: virtual dev::Exception {};
 struct InvalidTimestamp: virtual dev::Exception {};
 struct InvalidLogBloom: virtual dev::Exception {};
 class InvalidNonce: virtual public dev::Exception {};
+class InvalidBlockHeaderItemCount: virtual public dev::Exception {};
 class InvalidBlockNonce: virtual public dev::Exception {};
 struct InvalidParentHash: virtual dev::Exception {};
 struct InvalidNumber: virtual dev::Exception {};