diff --git a/builtin/v13/market/market_state.go b/builtin/v13/market/market_state.go
index 344dc1e0..af6acc40 100644
--- a/builtin/v13/market/market_state.go
+++ b/builtin/v13/market/market_state.go
@@ -194,7 +194,7 @@ func validateAndComputeDealWeight(proposals *DealArray, dealIDs []abi.DealID, mi
 
 		// Compute deal weight
 		totalDealSpace += uint64(proposal.PieceSize)
-		dealSpaceTime := DealWeight(proposal)
+		dealSpaceTime := DealWeight(proposal, sectorExpiry, sectorActivation)
 		if proposal.VerifiedDeal {
 			totalVerifiedSpaceTime = big.Add(totalVerifiedSpaceTime, dealSpaceTime)
 		} else {
diff --git a/builtin/v13/market/policy.go b/builtin/v13/market/policy.go
index 48c4481c..b23af725 100644
--- a/builtin/v13/market/policy.go
+++ b/builtin/v13/market/policy.go
@@ -55,8 +55,8 @@ func DealClientCollateralBounds(_ abi.PaddedPieceSize, _ abi.ChainEpoch) (min ab
 }
 
 // Computes the weight for a deal proposal, which is a function of its size and duration.
-func DealWeight(proposal *DealProposal) abi.DealWeight {
-	dealDuration := big.NewInt(int64(proposal.Duration()))
+func DealWeight(proposal *DealProposal, sectorExpiry abi.ChainEpoch, sectorActivation abi.ChainEpoch) abi.DealWeight {
+	dealDuration := big.NewInt(int64(sectorExpiry - sectorActivation))
 	dealSize := big.NewIntUnsigned(uint64(proposal.PieceSize))
 	dealSpaceTime := big.Mul(dealDuration, dealSize)
 	return dealSpaceTime
diff --git a/builtin/v14/market/market_state.go b/builtin/v14/market/market_state.go
index a11a077d..c7699222 100644
--- a/builtin/v14/market/market_state.go
+++ b/builtin/v14/market/market_state.go
@@ -194,7 +194,7 @@ func validateAndComputeDealWeight(proposals *DealArray, dealIDs []abi.DealID, mi
 
 		// Compute deal weight
 		totalDealSpace += uint64(proposal.PieceSize)
-		dealSpaceTime := DealWeight(proposal)
+		dealSpaceTime := DealWeight(proposal, sectorExpiry, sectorActivation)
 		if proposal.VerifiedDeal {
 			totalVerifiedSpaceTime = big.Add(totalVerifiedSpaceTime, dealSpaceTime)
 		} else {
diff --git a/builtin/v14/market/policy.go b/builtin/v14/market/policy.go
index 48c4481c..b23af725 100644
--- a/builtin/v14/market/policy.go
+++ b/builtin/v14/market/policy.go
@@ -55,8 +55,8 @@ func DealClientCollateralBounds(_ abi.PaddedPieceSize, _ abi.ChainEpoch) (min ab
 }
 
 // Computes the weight for a deal proposal, which is a function of its size and duration.
-func DealWeight(proposal *DealProposal) abi.DealWeight {
-	dealDuration := big.NewInt(int64(proposal.Duration()))
+func DealWeight(proposal *DealProposal, sectorExpiry abi.ChainEpoch, sectorActivation abi.ChainEpoch) abi.DealWeight {
+	dealDuration := big.NewInt(int64(sectorExpiry - sectorActivation))
 	dealSize := big.NewIntUnsigned(uint64(proposal.PieceSize))
 	dealSpaceTime := big.Mul(dealDuration, dealSize)
 	return dealSpaceTime