diff --git a/libethereum/BlockChainSync.cpp b/libethereum/BlockChainSync.cpp
index 817bc8fc9..ba961e15c 100644
--- a/libethereum/BlockChainSync.cpp
+++ b/libethereum/BlockChainSync.cpp
@@ -68,9 +68,7 @@ DownloadMan& BlockChainSync::downloadMan()
 
 void BlockChainSync::abortSync()
 {
-	DEV_INVARIANT_CHECK;
 	downloadMan().resetToChain(h256s());
-	DEV_INVARIANT_CHECK;
 }
 
 void BlockChainSync::onPeerStatus(std::shared_ptr<EthereumPeer> _peer)
diff --git a/libp2p/Capability.cpp b/libp2p/Capability.cpp
index 2b8e6be63..23d66302b 100644
--- a/libp2p/Capability.cpp
+++ b/libp2p/Capability.cpp
@@ -28,7 +28,7 @@ using namespace std;
 using namespace dev;
 using namespace dev::p2p;
 
-Capability::Capability(std::shared_ptr<Session> _s, HostCapabilityFace* _h, unsigned _idOffset): m_session(_s), m_hostCap(_h), m_idOffset(_idOffset)
+Capability::Capability(std::shared_ptr<Session> _s, HostCapabilityFace* _h, unsigned _idOffset): m_session(std::weak_ptr<Session>(_s)), m_hostCap(_h), m_idOffset(_idOffset)
 {
 	clog(NetConnect) << "New session for capability" << m_hostCap->name() << "; idOffset:" << m_idOffset;
 }