diff --git a/cmd/hivechain/genesis.go b/cmd/hivechain/genesis.go
index c482280268..35165d46f1 100644
--- a/cmd/hivechain/genesis.go
+++ b/cmd/hivechain/genesis.go
@@ -41,8 +41,8 @@ var (
 		"muirglacier",
 		"berlin",
 		"london",
-		"arrowglacier",
-		"grayglacier",
+		// "arrowglacier", "grayglacier" forks were difficulty bomb changes. They are not
+		// available here because hive doesn't support configuring them on clients.
 		"merge",
 	}
 
@@ -98,10 +98,6 @@ func (cfg *generatorConfig) createChainConfig() *params.ChainConfig {
 			chaincfg.BerlinBlock = new(big.Int).SetUint64(b)
 		case "london":
 			chaincfg.LondonBlock = new(big.Int).SetUint64(b)
-		case "arrowglacier":
-			chaincfg.ArrowGlacierBlock = new(big.Int).SetUint64(b)
-		case "grayglacier":
-			chaincfg.GrayGlacierBlock = new(big.Int).SetUint64(b)
 		case "merge":
 			chaincfg.MergeNetsplitBlock = new(big.Int).SetUint64(b)
 			chaincfg.TerminalTotalDifficultyPassed = true
diff --git a/cmd/hivechain/output_forkenv.go b/cmd/hivechain/output_forkenv.go
index 25f7f65d40..7a2018e04f 100644
--- a/cmd/hivechain/output_forkenv.go
+++ b/cmd/hivechain/output_forkenv.go
@@ -40,8 +40,6 @@ func (g *generator) writeForkEnv() error {
 	setNum("HIVE_FORK_PETERSBURG", cfg.PetersburgBlock)
 	setNum("HIVE_FORK_ISTANBUL", cfg.IstanbulBlock)
 	setNum("HIVE_FORK_MUIR_GLACIER", cfg.MuirGlacierBlock)
-	setNum("HIVE_FORK_ARROW_GLACIER", cfg.ArrowGlacierBlock)
-	setNum("HIVE_FORK_GRAY_GLACIER", cfg.GrayGlacierBlock)
 	setNum("HIVE_FORK_BERLIN", cfg.BerlinBlock)
 	setNum("HIVE_FORK_LONDON", cfg.LondonBlock)
 	setNum("HIVE_MERGE_BLOCK_ID", cfg.MergeNetsplitBlock)