diff --git a/src/main.cpp b/src/main.cpp
index d78003829..210d40265 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -3234,6 +3234,8 @@ bool CheckBlock(int32_t height,CBlockIndex *pindex,const CBlock& block, CValidat
         fprintf(stderr,"CheckBlockHeader error in CheckBlock\n");
         return false;
     }
+    if ( fCheckPOW && !CheckEquihashSolution(&block, Params()) )
+        return state.DoS(100, error("CheckBlockHeader(): Equihash solution invalid"),REJECT_INVALID, "invalid-solution");
     komodo_block2pubkey33(pubkey33,(CBlock *)&block);
     if ( fCheckPOW && !CheckProofOfWork(height,pubkey33,block.GetHash(), block.nBits, Params().GetConsensus()) )
         return state.DoS(50, error("CheckBlock(): proof of work failed"),REJECT_INVALID, "high-hash");
diff --git a/src/miner.cpp b/src/miner.cpp
index 83cf93fcf..e3743fe35 100644
--- a/src/miner.cpp
+++ b/src/miner.cpp
@@ -861,6 +861,12 @@ void static BitcoinMiner()
                         //     fprintf(stderr," missed target\n");
                         return false;
                     }
+                    CValidationState tmpstate;
+                    if ( !TestBlockValidity(tmpstate, *pblock, pindexPrev, true, false))
+                    {
+                        fprintf(stderr,"formerly valid mining block became invalid\n");
+                        break;
+                    }
                     if ( /*ASSETCHAINS_SYMBOL[0] == 0 &&*/ Mining_start != 0 && time(NULL) < Mining_start+roundrobin_delay )
                     {
                         //printf("Round robin diff sleep %d\n",(int32_t)(Mining_start+roundrobin_delay-time(NULL)));
@@ -1002,12 +1008,6 @@ void static BitcoinMiner()
                     // Changing pblock->nTime can change work required on testnet:
                     hashTarget.SetCompact(pblock->nBits);
                 }
-                CValidationState tmpstate;
-                if ( !TestBlockValidity(tmpstate, *pblock, pindexPrev, true, false))
-                {
-                    fprintf(stderr,"formerly valid mining block became invalid, likely due to tx expiration\n");
-                    break;
-                }
             }
         }
     }