diff --git a/CHANGELOG.md b/CHANGELOG.md
index 2be45af7632..deab90d1df2 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -19,7 +19,7 @@
 
 ## 👌 Improvements
 - fix(gateway): return `ErrFilterNotFound` error instead of empty result for unknown filter IDs in `EthGetFilterLogs` ([filecoin-project/lotus#13519](https://github.com/filecoin-project/lotus/pull/13519))
-- feat(basefee)!: premium-based base fee adjustment, activating in nv28 ([filecoin-project/lotus#13531](https://github.com/filecoin-project/lotus/pull/13531))
+- feat(basefee)!: premium-based base fee adjustment (FIP-0115), which may be included in a future upgrade ([filecoin-project/lotus#13531](https://github.com/filecoin-project/lotus/pull/13531))
 
 # Node and Miner v1.35.0 / 2026-02-19
 
diff --git a/chain/store/basefee.go b/chain/store/basefee.go
index 4ebcc65656c..f549bb98af9 100644
--- a/chain/store/basefee.go
+++ b/chain/store/basefee.go
@@ -54,10 +54,10 @@ func (cs *ChainStore) ComputeBaseFee(ctx context.Context, ts *types.TipSet) (abi
 	if buildconstants.UpgradeBreezeHeight >= 0 && ts.Height() > buildconstants.UpgradeBreezeHeight && ts.Height() < buildconstants.UpgradeBreezeHeight+buildconstants.BreezeGasTampingDuration {
 		return abi.NewTokenAmount(100), nil
 	}
-	if ts.Height() < buildconstants.UpgradeXxHeight {
-		return cs.ComputeNextBaseFeeFromUtilization(ctx, ts)
+	if cs.fip0115BaseFeeHeight >= 0 && ts.Height() >= cs.fip0115BaseFeeHeight {
+		return cs.ComputeNextBaseFeeFromPremiums(ctx, ts)
 	}
-	return cs.ComputeNextBaseFeeFromPremiums(ctx, ts)
+	return cs.ComputeNextBaseFeeFromUtilization(ctx, ts)
 }
 
 func (cs *ChainStore) ComputeNextBaseFeeFromUtilization(ctx context.Context, ts *types.TipSet) (abi.TokenAmount, error) {
diff --git a/chain/store/store.go b/chain/store/store.go
index 438c0a7855e..c28ddcd1613 100644
--- a/chain/store/store.go
+++ b/chain/store/store.go
@@ -129,6 +129,8 @@ type ChainStore struct {
 
 	storeEvents bool
 
+	fip0115BaseFeeHeight abi.ChainEpoch
+
 	cancelFn context.CancelFunc
 	wg       sync.WaitGroup
 }
@@ -156,6 +158,7 @@ func NewChainStore(chainBs bstore.Blockstore, stateBs bstore.Blockstore, ds dsto
 		tsCache:              tsc,
 		cancelFn:             cancel,
 		journal:              j,
+		fip0115BaseFeeHeight: -1,
 	}
 
 	cs.evtTypes = [1]journal.EventType{
@@ -1329,6 +1332,12 @@ func (cs *ChainStore) IsStoringEvents() bool {
 	return cs.storeEvents
 }
 
+// SetFIP0115Height sets the epoch at which FIP-0115 base fee calculation activates.
+// A value of -1 disables it.
+func (cs *ChainStore) SetFIP0115Height(height int64) {
+	cs.fip0115BaseFeeHeight = abi.ChainEpoch(height)
+}
+
 // true if ts1 wins according to the filecoin tie-break rule
 func breakWeightTie(ts1, ts2 *types.TipSet) bool {
 	s := len(ts1.Blocks())
diff --git a/documentation/en/default-lotus-config.toml b/documentation/en/default-lotus-config.toml
index 43d549766cc..473375588f6 100644
--- a/documentation/en/default-lotus-config.toml
+++ b/documentation/en/default-lotus-config.toml
@@ -147,6 +147,14 @@
   # env var: LOTUS_FEES_DEFAULTMAXFEE
   #DefaultMaxFee = "0.07 FIL"
 
+  # FIP0115Height sets the epoch at which FIP-0115 base fee calculation activates.
+  # Set to -1 to disable.
+  # WARNING: This is a consensus-breaking change and should only be used for testing.
+  #
+  # type: int64
+  # env var: LOTUS_FEES_FIP0115HEIGHT
+  #FIP0115Height = -1
+
 
 [Chainstore]
   # type: bool
diff --git a/node/builder.go b/node/builder.go
index 107c0e6f4e5..a87437b3e37 100644
--- a/node/builder.go
+++ b/node/builder.go
@@ -134,6 +134,7 @@ const (
 	SetApiEndpointKey
 
 	StoreEventsKey
+	SetFIP0115BaseFeeHeightKey
 
 	InitChainIndexerKey
 	InitApiV2Key
diff --git a/node/builder_chain.go b/node/builder_chain.go
index 4bcaf578b37..9f862173326 100644
--- a/node/builder_chain.go
+++ b/node/builder_chain.go
@@ -267,6 +267,10 @@ func ConfigFullNode(c interface{}) Option {
 		// as it enables us to serve logs in eth_getTransactionReceipt.
 		If(cfg.Fevm.EnableEthRPC || cfg.Events.EnableActorEventsAPI || cfg.ChainIndexer.EnableIndexer, Override(StoreEventsKey, modules.EnableStoringEvents)),
 
+		Override(SetFIP0115BaseFeeHeightKey, func(cs *store.ChainStore) {
+			cs.SetFIP0115Height(cfg.Fees.FIP0115Height)
+		}),
+
 		If(cfg.Wallet.RemoteBackend != "",
 			Override(new(*remotewallet.RemoteWallet), remotewallet.SetupRemoteWallet(cfg.Wallet.RemoteBackend)),
 		),
diff --git a/node/config/def.go b/node/config/def.go
index 5f8fab4b2ef..0599a812535 100644
--- a/node/config/def.go
+++ b/node/config/def.go
@@ -67,6 +67,7 @@ func DefaultFullNode() *FullNode {
 
 		Fees: FeeConfig{
 			DefaultMaxFee: DefaultDefaultMaxFee(),
+			FIP0115Height: -1,
 		},
 
 		Chainstore: Chainstore{
diff --git a/node/config/doc_gen.go b/node/config/doc_gen.go
index ba82e1e3405..47f1f9083c3 100644
--- a/node/config/doc_gen.go
+++ b/node/config/doc_gen.go
@@ -270,6 +270,14 @@ rewards. This address should have adequate funds to cover gas fees.`,
 
 			Comment: ``,
 		},
+		{
+			Name: "FIP0115Height",
+			Type: "int64",
+
+			Comment: `FIP0115Height sets the epoch at which FIP-0115 base fee calculation activates.
+Set to -1 to disable.
+WARNING: This is a consensus-breaking change and should only be used for testing.`,
+		},
 	},
 	"FevmConfig": {
 		{
diff --git a/node/config/types.go b/node/config/types.go
index f6a6e026007..fb8ebb60cfb 100644
--- a/node/config/types.go
+++ b/node/config/types.go
@@ -525,6 +525,11 @@ type Wallet struct {
 
 type FeeConfig struct {
 	DefaultMaxFee types.FIL
+
+	// FIP0115Height sets the epoch at which FIP-0115 base fee calculation activates.
+	// Set to -1 to disable.
+	// WARNING: This is a consensus-breaking change and should only be used for testing.
+	FIP0115Height int64
 }
 
 type FevmConfig struct {