diff --git a/libethcore/Common.h b/libethcore/Common.h
index bce95e8d6..63ecb67fd 100644
--- a/libethcore/Common.h
+++ b/libethcore/Common.h
@@ -24,7 +24,7 @@
 #pragma once
 
 // define version
-#define ETH_VERSION 0.5.5
+#define ETH_VERSION 0.5.6
 
 // way to many uint to size_t warnings in 32 bit build
 #ifdef _M_IX86
diff --git a/libethereum/CommonEth.cpp b/libethereum/CommonEth.cpp
index f65519a35..ab07bfbec 100644
--- a/libethereum/CommonEth.cpp
+++ b/libethereum/CommonEth.cpp
@@ -28,7 +28,7 @@ using namespace eth;
 
 //#define ETH_ADDRESS_DEBUG 1
 
-const unsigned eth::c_protocolVersion = 14;
+const unsigned eth::c_protocolVersion = 15;
 
 static const vector<pair<u256, string>> g_units =
 {