diff --git a/book/src/checkpoint-sync.md b/book/src/checkpoint-sync.md
index 893c545cb..47dc03b20 100644
--- a/book/src/checkpoint-sync.md
+++ b/book/src/checkpoint-sync.md
@@ -97,7 +97,7 @@ You can opt-in to reconstructing all of the historic states by providing the
 The database keeps track of three markers to determine the availability of historic blocks and
 states:
 
-* `oldest_block_slot`: All blocks with slots less than or equal to this value are available in the
+* `oldest_block_slot`: All blocks with slots greater than or equal to this value are available in the
   database. Additionally, the genesis block is always available.
 * `state_lower_limit`: All states with slots _less than or equal to_ this value are available in
   the database. The minimum value is 0, indicating that the genesis state is always available.