diff --git a/chains.yamale.yaml b/chains.yamale.yaml
index a3394da..1788a8c 100644
--- a/chains.yamale.yaml
+++ b/chains.yamale.yaml
@@ -27,6 +27,7 @@ settings:
   fork-choice: regex('^quorum$|^height$', required=False)
   mev-critical: bool(required=False)
   disabled: bool(required=False)
+  fork-tolerance: int(required=False)
 
 ---
 lags:
@@ -53,4 +54,4 @@ chain:
   net-version: int(required=False)
   settings: map(str(), any(), required=False)
   lower-bounds: map(str(), any(), required=False)
-  method-spec: str(required=False)
\ No newline at end of file
+  method-spec: str(required=False)
diff --git a/chains.yaml b/chains.yaml
index b825347..fa05982 100644
--- a/chains.yaml
+++ b/chains.yaml
@@ -2161,6 +2161,7 @@ chain-settings:
       settings:
         method-spec: "sei"
         expected-block-time: 200ms
+        fork-tolerance: 2
         options:
           validate-peers: false
           validate-syncing: false # does not support eth_syncing