diff --git a/src/main/resources/chains.yaml b/src/main/resources/chains.yaml
index 2c061bd5..17e89041 100644
--- a/src/main/resources/chains.yaml
+++ b/src/main/resources/chains.yaml
@@ -14,3 +14,19 @@ chain-settings:
       lags:
         syncing: 20
         lagging: 10
+    - id: arbitrum
+      lags:
+        syncing: 20
+        lagging: 10
+    - id: arbitrum-testnet
+      lags:
+        syncing: 20
+        lagging: 10
+    - id: optimism
+      lags:
+        syncing: 20
+        lagging: 10
+    - id: optimism-testnet
+      lags:
+        syncing: 20
+        lagging: 10
diff --git a/src/test/groovy/io/emeraldpay/dshackle/config/ChainsConfigReaderSpec.groovy b/src/test/groovy/io/emeraldpay/dshackle/config/ChainsConfigReaderSpec.groovy
index 6d674be4..529a36b8 100644
--- a/src/test/groovy/io/emeraldpay/dshackle/config/ChainsConfigReaderSpec.groovy
+++ b/src/test/groovy/io/emeraldpay/dshackle/config/ChainsConfigReaderSpec.groovy
@@ -40,7 +40,7 @@ class ChainsConfigReaderSpec extends Specification {
         pol.syncingLagSize == 20
 
         opt.laggingLagSize == 3
-        opt.syncingLagSize == 6
+        opt.syncingLagSize == 20
 
         sep.laggingLagSize == 1
         sep.syncingLagSize == 10