diff --git a/src/netbase.cpp b/src/netbase.cpp
index e3cb4e706..3fd779910 100644
--- a/src/netbase.cpp
+++ b/src/netbase.cpp
@@ -980,7 +980,7 @@ std::vector<unsigned char> CNetAddr::GetGroup() const
         nBits -= 8;
     }
     if (nBits > 0)
-        vchRet.push_back(GetByte(15 - nStartByte) | ((1 << nBits) - 1));
+        vchRet.push_back(GetByte(15 - nStartByte) | ((1 << (8 - nBits)) - 1));
 
     return vchRet;
 }