static bool ProcessBlockFound( const CBlock * const block, const CChainParams & chainparams )
 {
-    // Found a solution
-    LogPrintf( "%s\n", block->ToString() ) ;
-    LogPrintf( "generated %s\n", FormatMoney( block->vtx[0]->vout[0].nValue ) ) ;
+    assert( block != nullptr ) ;
+    CBlockIndex* lastTip = chainActive.Tip() ; /* mapBlockIndex[ chainActive.Tip()->GetBlockSha256Hash() ] */

     {
         LOCK( cs_main );
-        if ( block->hashPrevBlock != chainActive.Tip()->GetBlockSha256Hash() )
-            return error( "ProcessBlockFound: generated block is stale" ) ;
+
+        if ( lastTip != nullptr &&
+                block->hashPrevBlock != lastTip->GetBlockSha256Hash() )
+        {   // generated block isn't above the chain's current tip block
+            std::string why = "lost in the chain" ;
+
+            // is it above the previous block?
+            if ( lastTip->pprev != nullptr &&
+                    lastTip->pprev->GetBlockSha256Hash() == block->hashPrevBlock )
+            {
+                CValidationState state ;
+                RejectBlock( state, Params(), lastTip ) ;
+                if ( state.IsValid() )
+                    if ( ActivateBestChain( state, Params() ) ) why = "" ;
+                else
+                    why = state.GetRejectReason() ;
+            }
+
+            if ( ! why.empty() ) {
+                if ( lastTip->nStatus & BLOCK_FAILED_MASK ) ResetBlockFailureFlags( lastTip ) ;
+                return error( "%s: generated block is stale (%s)", __func__, why ) ;
+            }
+        }
     }

+    // Found a solution
+    LogPrintf( "%s\n", block->ToString() ) ;
+    LogPrintf( "reward %s\n", FormatMoney( block->vtx[0]->vout[0].nValue ) ) ;
+
     // Say about the new block
     GetMainSignals().BlockFound( block->GetSha256Hash() ) ;

     // Process this block the same as if it were received from another node
-    if ( ! ProcessNewBlock( chainparams, std::make_shared< const CBlock >( *block ), true, nullptr ) )
+    if ( ! ProcessNewBlock( chainparams, std::make_shared< const CBlock >( *block ), true, nullptr ) ) {
+        if ( lastTip->nStatus & BLOCK_FAILED_MASK ) {
+            LOCK( cs_main );
+            ResetBlockFailureFlags( lastTip ) ;
+        }
         return error( "ProcessBlockFound: ProcessNewBlock, block not accepted" ) ;
+    }
+
+    if ( lastTip->nStatus & BLOCK_FAILED_MASK ) {
+        LOCK( cs_main );
+        ResetBlockFailureFlags( lastTip ) ; // it was just to rewind, not to mark as rejected forever
+    }

     return true ;
 }