diff --git a/op-program/host/kvstore/local.go b/op-program/host/kvstore/local.go
index 3db9beccb7b5..b81b427e4150 100644
--- a/op-program/host/kvstore/local.go
+++ b/op-program/host/kvstore/local.go
@@ -48,8 +48,14 @@ func (s *LocalPreimageSource) Get(key common.Hash) ([]byte, error) {
 		}
 		return binary.BigEndian.AppendUint64(nil, chainID), nil
 	case l2ChainConfigKey:
+		if !s.config.IsCustomChainConfig {
+			return nil, ErrNotFound
+		}
 		return json.Marshal(s.config.L2ChainConfig)
 	case rollupKey:
+		if !s.config.IsCustomChainConfig {
+			return nil, ErrNotFound
+		}
 		return json.Marshal(s.config.Rollup)
 	default:
 		return nil, ErrNotFound
diff --git a/op-program/host/kvstore/local_test.go b/op-program/host/kvstore/local_test.go
index f5e71f9d893b..7d379024aa2e 100644
--- a/op-program/host/kvstore/local_test.go
+++ b/op-program/host/kvstore/local_test.go
@@ -33,8 +33,8 @@ func TestLocalPreimageSource(t *testing.T) {
 		{"L2Claim", l2ClaimKey, cfg.L2Claim.Bytes()},
 		{"L2ClaimBlockNumber", l2ClaimBlockNumberKey, binary.BigEndian.AppendUint64(nil, cfg.L2ClaimBlockNumber)},
 		{"L2ChainID", l2ChainIDKey, binary.BigEndian.AppendUint64(nil, cfg.L2ChainConfig.ChainID.Uint64())},
-		{"Rollup", rollupKey, asJson(t, cfg.Rollup)},
-		{"ChainConfig", l2ChainConfigKey, asJson(t, cfg.L2ChainConfig)},
+		{"Rollup", rollupKey, nil},             // Only available for custom chain configs
+		{"ChainConfig", l2ChainConfigKey, nil}, // Only available for custom chain configs
 		{"Unknown", preimage.LocalIndexKey(1000).PreimageKey(), nil},
 	}
 	for _, test := range tests {
@@ -50,6 +50,25 @@ func TestLocalPreimageSource(t *testing.T) {
 	}
 }
 
+func TestGetCustomChainConfigPreimages(t *testing.T) {
+	cfg := &config.Config{
+		Rollup:              chaincfg.OPSepolia(),
+		IsCustomChainConfig: true,
+		L1Head:              common.HexToHash("0x1111"),
+		L2OutputRoot:        common.HexToHash("0x2222"),
+		L2Claim:             common.HexToHash("0x3333"),
+		L2ClaimBlockNumber:  1234,
+		L2ChainConfig:       params.SepoliaChainConfig,
+	}
+	source := NewLocalPreimageSource(cfg)
+	actualRollup, err := source.Get(rollupKey)
+	require.NoError(t, err)
+	require.Equal(t, asJson(t, cfg.Rollup), actualRollup)
+	actualChainConfig, err := source.Get(l2ChainConfigKey)
+	require.NoError(t, err)
+	require.Equal(t, asJson(t, cfg.L2ChainConfig), actualChainConfig)
+}
+
 func asJson(t *testing.T, v any) []byte {
 	d, err := json.Marshal(v)
 	require.NoError(t, err)