diff --git a/src/main.cpp b/src/main.cpp
index 3351e77c7..3f568df7c 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -3798,7 +3798,8 @@ bool AcceptBlockHeader(int32_t *futureblockp,const CBlockHeader& block, CValidat
     if (miSelf != mapBlockIndex.end())
     {
         // Block header is already known.
-        pindex = miSelf->second;
+        if ( (pindex= miSelf->second) == 0 )
+            pindex = AddToBlockIndex(block);
         if (ppindex)
             *ppindex = pindex;
         if ( pindex != 0 && pindex->nStatus & BLOCK_FAILED_MASK )