diff --git a/src/main.cpp b/src/main.cpp
index bbc083cec..6cf08aced 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -1158,6 +1158,11 @@ void CBlockHeader::SetAuxPow(CAuxPow* pow)
     auxpow.reset(pow);
 }
 
+bool IsAuxPowVersion(int nVersion)
+{
+    return (nVersion == BLOCK_VERSION_AUXPOW_WITH_AUX || nVersion == BLOCK_VERSION_AUXPOW_WITHOUT_AUX);
+}
+
 uint256 static GetOrphanRoot(const uint256& hash)
 {
     map<uint256, COrphanBlock*>::iterator it = mapOrphanBlocks.find(hash);
@@ -2066,10 +2071,9 @@ void static UpdateTip(CBlockIndex *pindexNew) {
     {
         int nUpgraded = 0;
         const CBlockIndex* pindex = chainActive.Tip();
-        int nAuxVersion = CBlockHeader::CURRENT_VERSION | (AUXPOW_CHAIN_ID * BLOCK_VERSION_CHAIN_START);
         for (int i = 0; i < 100 && pindex != NULL; i++)
         {
-            if (pindex->nVersion > CBlock::CURRENT_VERSION && pindex->nVersion != nAuxVersion)
+            if (pindex->nVersion > CBlock::CURRENT_VERSION && !IsAuxPowVersion(pindex->nVersion))
                 ++nUpgraded;
             pindex = pindex->pprev;
         }
diff --git a/src/main.h b/src/main.h
index cd512846e..acea707ea 100644
--- a/src/main.h
+++ b/src/main.h
@@ -79,6 +79,14 @@ static const int MAX_BLOCKS_IN_TRANSIT_PER_PEER = 128;
 /** Timeout in seconds before considering a block download peer unresponsive. */
 static const unsigned int BLOCK_DOWNLOAD_TIMEOUT = 60;
 
+/** AuxPow Block versions for sanity checks. */
+/** bare AuxPoW block version which will be modulated further. */
+static const int BLOCK_VERSION_AUXPOW_BARE = CBlockHeader::CURRENT_VERSION | (AUXPOW_CHAIN_ID * BLOCK_VERSION_CHAIN_START);
+/** version when AuxPoW exists on the block */
+static const int BLOCK_VERSION_AUXPOW_WITH_AUX = BLOCK_VERSION_AUXPOW_BARE | BLOCK_VERSION_AUXPOW;
+/** version when no AuxPoW exists on the block */
+static const int BLOCK_VERSION_AUXPOW_WITHOUT_AUX = BLOCK_VERSION_AUXPOW_BARE & ~BLOCK_VERSION_AUXPOW;
+
 #ifdef USE_UPNP
 static const int fHaveUPnP = true;
 #else
@@ -185,6 +193,9 @@ unsigned int GetNextWorkRequired(const CBlockIndex* pindexLast, const CBlockHead
 
 void UpdateTime(CBlockHeader& block, const CBlockIndex* pindexPrev);
 
+/** Determine whether the block version is modulated with auxpow logic */
+bool IsAuxPowVersion(int nVersion);
+
 /** Create a new block index entry for a given block hash */
 CBlockIndex * InsertBlockIndex(uint256 hash);
 /** Verify a signature */