diff --git a/proto/cosmos/upgrade/v1beta1/upgrade.proto b/proto/cosmos/upgrade/v1beta1/upgrade.proto
index 826440e5d7..6d6839ca56 100644
--- a/proto/cosmos/upgrade/v1beta1/upgrade.proto
+++ b/proto/cosmos/upgrade/v1beta1/upgrade.proto
@@ -40,7 +40,6 @@ message Plan {
   // previous version of the chain.
   // This will allow IBC connections to persist smoothly across planned chain upgrades
   google.protobuf.Any upgraded_client_state = 5 [(gogoproto.moretags) = "yaml:\"upgraded_client_state\""];
-  ;
 }
 
 // SoftwareUpgradeProposal is a gov Content type for initiating a software
diff --git a/x/upgrade/types/proposal.go b/x/upgrade/types/proposal.go
index d4ae8422ea..a8ea9b6290 100644
--- a/x/upgrade/types/proposal.go
+++ b/x/upgrade/types/proposal.go
@@ -3,6 +3,7 @@ package types
 import (
 	"fmt"
 
+	codectypes "github.com/cosmos/cosmos-sdk/codec/types"
 	gov "github.com/cosmos/cosmos-sdk/x/gov/types"
 )
 
@@ -17,6 +18,7 @@ func NewSoftwareUpgradeProposal(title, description string, plan Plan) gov.Conten
 
 // Implements Proposal Interface
 var _ gov.Content = &SoftwareUpgradeProposal{}
+var _ codectypes.UnpackInterfacesMessage = SoftwareUpgradeProposal{}
 
 func init() {
 	gov.RegisterProposalType(ProposalTypeSoftwareUpgrade)
@@ -43,6 +45,11 @@ func (sup SoftwareUpgradeProposal) String() string {
 `, sup.Title, sup.Description)
 }
 
+// UnpackInterfaces implements UnpackInterfacesMessage.UnpackInterfaces
+func (sup SoftwareUpgradeProposal) UnpackInterfaces(unpacker codectypes.AnyUnpacker) error {
+	return sup.Plan.UnpackInterfaces(unpacker)
+}
+
 func NewCancelSoftwareUpgradeProposal(title, description string) gov.Content {
 	return &CancelSoftwareUpgradeProposal{title, description}
 }
@@ -50,19 +57,19 @@ func NewCancelSoftwareUpgradeProposal(title, description string) gov.Content {
 // Implements Proposal Interface
 var _ gov.Content = &CancelSoftwareUpgradeProposal{}
 
-func (sup *CancelSoftwareUpgradeProposal) GetTitle() string       { return sup.Title }
-func (sup *CancelSoftwareUpgradeProposal) GetDescription() string { return sup.Description }
-func (sup *CancelSoftwareUpgradeProposal) ProposalRoute() string  { return RouterKey }
-func (sup *CancelSoftwareUpgradeProposal) ProposalType() string {
+func (csup *CancelSoftwareUpgradeProposal) GetTitle() string       { return csup.Title }
+func (csup *CancelSoftwareUpgradeProposal) GetDescription() string { return csup.Description }
+func (csup *CancelSoftwareUpgradeProposal) ProposalRoute() string  { return RouterKey }
+func (csup *CancelSoftwareUpgradeProposal) ProposalType() string {
 	return ProposalTypeCancelSoftwareUpgrade
 }
-func (sup *CancelSoftwareUpgradeProposal) ValidateBasic() error {
-	return gov.ValidateAbstract(sup)
+func (csup *CancelSoftwareUpgradeProposal) ValidateBasic() error {
+	return gov.ValidateAbstract(csup)
 }
 
-func (sup CancelSoftwareUpgradeProposal) String() string {
+func (csup CancelSoftwareUpgradeProposal) String() string {
 	return fmt.Sprintf(`Cancel Software Upgrade Proposal:
   Title:       %s
   Description: %s
-`, sup.Title, sup.Description)
+`, csup.Title, csup.Description)
 }
diff --git a/x/upgrade/types/proposal_test.go b/x/upgrade/types/proposal_test.go
index 8f5ffb07a7..d39b89135c 100644
--- a/x/upgrade/types/proposal_test.go
+++ b/x/upgrade/types/proposal_test.go
@@ -7,7 +7,10 @@ import (
 	"github.com/stretchr/testify/require"
 
 	"github.com/cosmos/cosmos-sdk/codec"
+	codectypes "github.com/cosmos/cosmos-sdk/codec/types"
 	gov "github.com/cosmos/cosmos-sdk/x/gov/types"
+	clienttypes "github.com/cosmos/cosmos-sdk/x/ibc/core/02-client/types"
+	ibctmtypes "github.com/cosmos/cosmos-sdk/x/ibc/light-clients/07-tendermint/types"
 	"github.com/cosmos/cosmos-sdk/x/upgrade/types"
 )
 
@@ -75,3 +78,41 @@ func TestContentAccessors(t *testing.T) {
 
 	}
 }
+
+// tests a software update proposal can be marshaled and unmarshaled, and the
+// client state can be unpacked
+func TestMarshalSoftwareUpdateProposal(t *testing.T) {
+	cs, err := clienttypes.PackClientState(&ibctmtypes.ClientState{})
+	require.NoError(t, err)
+
+	// create proposal
+	plan := types.Plan{
+		Name:                "upgrade ibc",
+		Height:              1000,
+		UpgradedClientState: cs,
+	}
+	content := types.NewSoftwareUpgradeProposal("title", "description", plan)
+	sup, ok := content.(*types.SoftwareUpgradeProposal)
+	require.True(t, ok)
+
+	// create codec
+	ir := codectypes.NewInterfaceRegistry()
+	types.RegisterInterfaces(ir)
+	clienttypes.RegisterInterfaces(ir)
+	gov.RegisterInterfaces(ir)
+	ibctmtypes.RegisterInterfaces(ir)
+	cdc := codec.NewProtoCodec(ir)
+
+	// marshal message
+	bz, err := cdc.MarshalJSON(sup)
+	require.NoError(t, err)
+
+	// unmarshal proposal
+	newSup := &types.SoftwareUpgradeProposal{}
+	err = cdc.UnmarshalJSON(bz, newSup)
+	require.NoError(t, err)
+
+	// unpack client state
+	_, err = clienttypes.UnpackClientState(newSup.Plan.UpgradedClientState)
+	require.NoError(t, err)
+}