diff --git a/src/net_processing.cpp b/src/net_processing.cpp
index 5c3ec5f7006..2c91b5cf0f5 100644
--- a/src/net_processing.cpp
+++ b/src/net_processing.cpp
@@ -1397,6 +1397,15 @@ void PeerManagerImpl::FindNextBlocksToDownload(const Peer& peer, unsigned int co
         return;
     }
 
+    // When we sync with AssumeUtxo and discover the snapshot is not in the peer's best chain, abort:
+    // We can't reorg to this chain due to missing undo data until the background sync has finished,
+    // so downloading blocks from it would be futile.
+    const CBlockIndex* snap_base{m_chainman.GetSnapshotBaseBlock()};
+    if (snap_base && state->pindexBestKnownBlock->GetAncestor(snap_base->nHeight) != snap_base) {
+        LogDebug(BCLog::NET, "Not downloading blocks from peer=%d, which doesn't have the snapshot block in its best chain.\n", peer.m_id);
+        return;
+    }
+
     if (state->pindexLastCommonBlock == nullptr) {
         // Bootstrap quickly by guessing a parent of our best tip is the forking point.
         // Guessing wrong in either direction is not a problem.