diff --git a/core/blockchain.go b/core/blockchain.go
index 38a129d4e..99a110f4f 100644
--- a/core/blockchain.go
+++ b/core/blockchain.go
@@ -255,6 +255,10 @@ func NewBlockChain(db ethdb.Database, cacheConfig *CacheConfig, genesis *Genesis
 	log.Info(strings.Repeat("-", 153))
 	log.Info("")
 
+	if chainConfig.IsOptimism() && chainConfig.RegolithTime == nil {
+		log.Warn("Optimism RegolithTime has not been set")
+	}
+
 	bc := &BlockChain{
 		chainConfig:   chainConfig,
 		cacheConfig:   cacheConfig,