diff --git a/src/validation.h b/src/validation.h
index e71877e06b..d2e927030b 100644
--- a/src/validation.h
+++ b/src/validation.h
@@ -447,7 +447,9 @@ void ReprocessBlocks(int nBlocks);
 bool CheckBlockHeader(const CBlockHeader& block, CValidationState& state, bool fCheckPOW = true);
 bool CheckBlock(const CBlock& block, CValidationState& state, bool fCheckPOW = true, bool fCheckMerkleRoot = true);
 
-/** Context-dependent validity checks */
+/** Context-dependent validity checks.
+ *  By "context", we mean only the previous block headers, but not the UTXO
+ *  set; UTXO-related validity checks are done in ConnectBlock(). */
 bool ContextualCheckBlockHeader(const CBlockHeader& block, CValidationState& state, CBlockIndex *pindexPrev);
 bool ContextualCheckBlock(const CBlock& block, CValidationState& state, CBlockIndex *pindexPrev);