diff --git a/zebra-state/src/constants.rs b/zebra-state/src/constants.rs
index 58094797..b91fe29d 100644
--- a/zebra-state/src/constants.rs
+++ b/zebra-state/src/constants.rs
@@ -24,7 +24,7 @@ pub const DATABASE_FORMAT_VERSION: u32 = 25;
 /// before we assume we are on a pre-NU5 legacy chain.
 ///
 /// Zebra usually only has to check back a few blocks, but on testnet it can be a long time between v5 transactions.
-pub const MAX_LEGACY_CHAIN_BLOCKS: usize = 10_000;
+pub const MAX_LEGACY_CHAIN_BLOCKS: usize = 100_000;
 
 /// The maximum number of block hashes allowed in `getblocks` responses in the Zcash network protocol.
 pub const MAX_FIND_BLOCK_HASHES_RESULTS: u32 = 500;