diff --git a/src/netgroup.cpp b/src/netgroup.cpp
index 3dc59725e1..c3162d0b28 100644
--- a/src/netgroup.cpp
+++ b/src/netgroup.cpp
@@ -71,7 +71,7 @@ std::vector<unsigned char> NetGroupManager::GetGroup(const CNetAddr& address) co
     // ...for the last byte, push nBits and for the rest of the byte push 1's
     if (nBits > 0) {
         assert(num_bytes < addr_bytes.size());
-        vchRet.push_back(addr_bytes[num_bytes] | ((1 << (8 - nBits)) - 1));
+        vchRet.push_back(addr_bytes[num_bytes + nStartByte] | ((1 << (8 - nBits)) - 1));
     }
 
     return vchRet;