diff --git a/chain/actors/policy/policy.go b/chain/actors/policy/policy.go
index a19a43aaa..31d83cd3d 100644
--- a/chain/actors/policy/policy.go
+++ b/chain/actors/policy/policy.go
@@ -28,7 +28,7 @@ const (
 func SetSupportedProofTypes(types ...abi.RegisteredSealProof) {
 	miner0.SupportedProofTypes = make(map[abi.RegisteredSealProof]struct{}, len(types))
 	miner2.PreCommitSealProofTypesV0 = make(map[abi.RegisteredSealProof]struct{}, len(types))
-	miner2.PreCommitSealProofTypesV7 = make(map[abi.RegisteredSealProof]struct{}, len(types))
+	miner2.PreCommitSealProofTypesV7 = make(map[abi.RegisteredSealProof]struct{}, len(types)*2)
 	miner2.PreCommitSealProofTypesV8 = make(map[abi.RegisteredSealProof]struct{}, len(types))
 
 	AddSupportedProofTypes(types...)