diff --git a/README.md b/README.md
index c7adb135d6..86f7713fd9 100644
--- a/README.md
+++ b/README.md
@@ -231,7 +231,8 @@ aware of and agree upon. This consists of a small JSON file (e.g. call it `genes
     "constantinopleBlock": 0,
     "petersburgBlock": 0,
     "istanbulBlock": 0,
-    "berlinBlock": 0
+    "berlinBlock": 0,
+    "londonBlock": 0
   },
   "alloc": {},
   "coinbase": "0x0000000000000000000000000000000000000000",