diff --git a/x/gov/keeper/msg_server.go b/x/gov/keeper/msg_server.go
index 86490944..df4036b7 100644
--- a/x/gov/keeper/msg_server.go
+++ b/x/gov/keeper/msg_server.go
@@ -13,6 +13,7 @@ import (
 
 type msgServer struct {
 	sdkv1.MsgServer
+	keeper *Keeper
 }
 
 // NewMsgServerImpl returns an implementation of the gov MsgServer interface
@@ -20,11 +21,27 @@ type msgServer struct {
 // We return an private type, as we do not want to do type casting in module.
 // Making it public adds no benefits.
 func NewMsgServerImpl(k *Keeper) *msgServer {
-	return &msgServer{MsgServer: govkeeper.NewMsgServerImpl(k.Keeper)}
+	return &msgServer{
+		MsgServer: govkeeper.NewMsgServerImpl(k.Keeper),
+		keeper:    k,
+	}
 }
 
 var _ v1.MsgServer = msgServer{}
 
+func mergeLegacyParamsWithSDKParams(current sdkv1.Params, legacy *v1.Params) sdkv1.Params {
+	updated := v1.ConvertAtomOneParamsToSDK(legacy)
+	if updated == nil {
+		return current
+	}
+
+	// atomone.gov.v1 cannot express these SDK-only fields, so preserve the live values.
+	updated.ProposalCancelRatio = current.ProposalCancelRatio
+	updated.ProposalCancelDest = current.ProposalCancelDest
+
+	return *updated
+}
+
 // SubmitProposal implements the MsgServer.SubmitProposal method.
 func (k msgServer) SubmitProposal(ctx context.Context, msg *v1.MsgSubmitProposal) (*v1.MsgSubmitProposalResponse, error) {
 	result, err := k.MsgServer.SubmitProposal(ctx, &sdkv1.MsgSubmitProposal{
@@ -103,9 +120,14 @@ func (k msgServer) Deposit(ctx context.Context, msg *v1.MsgDeposit) (*v1.MsgDepo
 
 // UpdateParams implements the MsgServer.UpdateParams method.
 func (k msgServer) UpdateParams(ctx context.Context, msg *v1.MsgUpdateParams) (*v1.MsgUpdateParamsResponse, error) {
-	_, err := k.MsgServer.UpdateParams(ctx, &sdkv1.MsgUpdateParams{
+	currentParams, err := k.keeper.Params.Get(ctx)
+	if err != nil {
+		return nil, err
+	}
+
+	_, err = k.MsgServer.UpdateParams(ctx, &sdkv1.MsgUpdateParams{
 		Authority: msg.GetAuthority(),
-		Params:    *v1.ConvertAtomOneParamsToSDK(&msg.Params),
+		Params:    mergeLegacyParamsWithSDKParams(currentParams, &msg.Params),
 	})
 	if err != nil {
 		return nil, err
diff --git a/x/gov/keeper/msg_server_test.go b/x/gov/keeper/msg_server_test.go
new file mode 100644
index 00000000..e17b88c8
--- /dev/null
+++ b/x/gov/keeper/msg_server_test.go
@@ -0,0 +1,24 @@
+package keeper
+
+import (
+	"testing"
+
+	authtypes "github.com/cosmos/cosmos-sdk/x/auth/types"
+	sdkv1 "github.com/cosmos/cosmos-sdk/x/gov/types/v1"
+	"github.com/stretchr/testify/require"
+
+	v1 "github.com/atomone-hub/atomone/x/gov/types/v1"
+)
+
+func TestMergeLegacyParamsWithSDKParamsPreservesSDKOnlyFields(t *testing.T) {
+	current := sdkv1.DefaultParams()
+	current.ProposalCancelRatio = "0.42"
+	current.ProposalCancelDest = authtypes.NewModuleAddress("distribution").String()
+	legacy := v1.DefaultParams()
+
+	merged := mergeLegacyParamsWithSDKParams(current, &legacy)
+
+	require.Equal(t, current.ProposalCancelRatio, merged.ProposalCancelRatio)
+	require.Equal(t, current.ProposalCancelDest, merged.ProposalCancelDest)
+	require.NoError(t, merged.ValidateBasic())
+}
diff --git a/x/gov/types/v1/wrapper.go b/x/gov/types/v1/wrapper.go
index 9b79ebcb..c58d63d0 100644
--- a/x/gov/types/v1/wrapper.go
+++ b/x/gov/types/v1/wrapper.go
@@ -424,6 +424,8 @@ func ConvertAtomOneParamsToSDK(atomoneParams *Params) *sdkv1.Params {
 		return nil
 	}
 
+	defaultParams := sdkv1.DefaultParams()
+
 	return &sdkv1.Params{
 		MinDeposit:                       atomoneParams.MinDeposit,
 		MaxDepositPeriod:                 atomoneParams.MaxDepositPeriod,
@@ -431,6 +433,8 @@ func ConvertAtomOneParamsToSDK(atomoneParams *Params) *sdkv1.Params {
 		Quorum:                           atomoneParams.Quorum,
 		Threshold:                        atomoneParams.Threshold,
 		MinInitialDepositRatio:           atomoneParams.MinInitialDepositRatio,
+		ProposalCancelRatio:              defaultParams.ProposalCancelRatio,
+		ProposalCancelDest:               defaultParams.ProposalCancelDest,
 		BurnVoteQuorum:                   atomoneParams.BurnVoteQuorum,
 		BurnProposalDepositPrevote:       atomoneParams.BurnProposalDepositPrevote,
 		MinDepositRatio:                  atomoneParams.MinDepositRatio,
diff --git a/x/gov/types/v1/wrapper_test.go b/x/gov/types/v1/wrapper_test.go
new file mode 100644
index 00000000..0561b0af
--- /dev/null
+++ b/x/gov/types/v1/wrapper_test.go
@@ -0,0 +1,19 @@
+package v1
+
+import (
+	"testing"
+
+	sdkv1 "github.com/cosmos/cosmos-sdk/x/gov/types/v1"
+	"github.com/stretchr/testify/require"
+)
+
+func TestConvertAtomOneParamsToSDKUsesSDKCancelDefaults(t *testing.T) {
+	params := DefaultParams()
+
+	sdkParams := ConvertAtomOneParamsToSDK(&params)
+	defaultParams := sdkv1.DefaultParams()
+
+	require.Equal(t, defaultParams.ProposalCancelRatio, sdkParams.ProposalCancelRatio)
+	require.Equal(t, defaultParams.ProposalCancelDest, sdkParams.ProposalCancelDest)
+	require.NoError(t, sdkParams.ValidateBasic())
+}