diff --git a/src/validation.h b/src/validation.h
index a3951a58c6..1e8770745d 100644
--- a/src/validation.h
+++ b/src/validation.h
@@ -1038,7 +1038,10 @@ public:
     }
 
 
-    /** Best header we've seen so far (used for getheaders queries' starting points). */
+    /** Best header we've seen so far for which the block is not known to be invalid
+        (used, among others, for getheaders queries' starting points).
+        In case of multiple best headers with the same work, it could point to any
+        because CBlockIndexWorkComparator tiebreaker rules are not applied. */
     CBlockIndex* m_best_header GUARDED_BY(::cs_main){nullptr};
 
     //! The total number of bytes available for us to use across all in-memory