diff --git a/foundation/src/main/resources/chains.yaml b/foundation/src/main/resources/chains.yaml
index dde239790..a4d947f7a 100644
--- a/foundation/src/main/resources/chains.yaml
+++ b/foundation/src/main/resources/chains.yaml
@@ -166,7 +166,7 @@ chain-settings:
           code: OPTIMISM_TESTNET
           grpcId: 10010
           short-names: [optimism-testnet, optimism-goerli]
-          chain-id: 0x1A4
+          chain-id: 0x1a4
     - id: bsc
       label: BNB Smart Chain
       settings:
diff --git a/src/main/kotlin/io/emeraldpay/dshackle/Global.kt b/src/main/kotlin/io/emeraldpay/dshackle/Global.kt
index 84aa6036d..1635189ef 100644
--- a/src/main/kotlin/io/emeraldpay/dshackle/Global.kt
+++ b/src/main/kotlin/io/emeraldpay/dshackle/Global.kt
@@ -54,7 +54,7 @@ class Global {
 
         fun chainByChainId(id: String): Chain {
             return Chain.values().find { chain ->
-                chain.chainId == id
+                chain.chainId.lowercase() == id.lowercase()
             } ?: Chain.UNSPECIFIED
         }