diff --git a/x/gov/keeper/migrations.go b/x/gov/keeper/migrations.go
index c643c6dd7b99..e0134012258f 100644
--- a/x/gov/keeper/migrations.go
+++ b/x/gov/keeper/migrations.go
@@ -17,5 +17,5 @@ func NewMigrator(keeper Keeper) Migrator {
 
 // Migrate1to2 migrates from version 1 to 2.
 func (m Migrator) Migrate1to2(ctx sdk.Context) error {
-	return v042.MigrateStore(ctx, m.keeper.storeKey)
+	return v042.MigrateStore(ctx, m.keeper.storeKey, m.keeper.cdc)
 }
diff --git a/x/gov/legacy/v040/types.go b/x/gov/legacy/v040/types.go
new file mode 100644
index 000000000000..babaa772b697
--- /dev/null
+++ b/x/gov/legacy/v040/types.go
@@ -0,0 +1,302 @@
+// Package v040 is take from:
+// https://github.com/cosmos/cosmos-sdk/blob/v0.41.1/x/gov/types/vote.go
+// by copy-pasted only the relevants parts for Vote.
+package v040
+
+import (
+	"fmt"
+	"io"
+	math_bits "math/bits"
+
+	"github.com/cosmos/cosmos-sdk/x/gov/types"
+)
+
+type Vote struct {
+	ProposalId uint64           `protobuf:"varint,1,opt,name=proposal_id,json=proposalId,proto3" json:"proposal_id,omitempty" yaml:"proposal_id"`
+	Voter      string           `protobuf:"bytes,2,opt,name=voter,proto3" json:"voter,omitempty"`
+	Option     types.VoteOption `protobuf:"varint,3,opt,name=option,proto3,enum=cosmos.gov.v1beta1.VoteOption" json:"option,omitempty"`
+}
+
+func (m *Vote) Reset()      { *m = Vote{} }
+func (*Vote) ProtoMessage() {}
+
+func (m *Vote) Size() (n int) {
+	if m == nil {
+		return 0
+	}
+	var l int
+	_ = l
+	if m.ProposalId != 0 {
+		n += 1 + sovGov(uint64(m.ProposalId))
+	}
+	l = len(m.Voter)
+	if l > 0 {
+		n += 1 + l + sovGov(uint64(l))
+	}
+	if m.Option != 0 {
+		n += 1 + sovGov(uint64(m.Option))
+	}
+	return n
+}
+
+func (m *Vote) Marshal() (dAtA []byte, err error) {
+	size := m.Size()
+	dAtA = make([]byte, size)
+	n, err := m.MarshalToSizedBuffer(dAtA[:size])
+	if err != nil {
+		return nil, err
+	}
+	return dAtA[:n], nil
+}
+
+func (m *Vote) MarshalTo(dAtA []byte) (int, error) {
+	size := m.Size()
+	return m.MarshalToSizedBuffer(dAtA[:size])
+}
+
+func (m *Vote) MarshalToSizedBuffer(dAtA []byte) (int, error) {
+	i := len(dAtA)
+	_ = i
+	var l int
+	_ = l
+	if m.Option != 0 {
+		i = encodeVarintGov(dAtA, i, uint64(m.Option))
+		i--
+		dAtA[i] = 0x18
+	}
+	if len(m.Voter) > 0 {
+		i -= len(m.Voter)
+		copy(dAtA[i:], m.Voter)
+		i = encodeVarintGov(dAtA, i, uint64(len(m.Voter)))
+		i--
+		dAtA[i] = 0x12
+	}
+	if m.ProposalId != 0 {
+		i = encodeVarintGov(dAtA, i, uint64(m.ProposalId))
+		i--
+		dAtA[i] = 0x8
+	}
+	return len(dAtA) - i, nil
+}
+
+func encodeVarintGov(dAtA []byte, offset int, v uint64) int {
+	offset -= sovGov(v)
+	base := offset
+	for v >= 1<<7 {
+		dAtA[offset] = uint8(v&0x7f | 0x80)
+		v >>= 7
+		offset++
+	}
+	dAtA[offset] = uint8(v)
+	return base
+}
+
+func sovGov(x uint64) (n int) {
+	return (math_bits.Len64(x|1) + 6) / 7
+}
+
+func (m *Vote) Unmarshal(dAtA []byte) error {
+	l := len(dAtA)
+	iNdEx := 0
+	for iNdEx < l {
+		preIndex := iNdEx
+		var wire uint64
+		for shift := uint(0); ; shift += 7 {
+			if shift >= 64 {
+				return ErrIntOverflowGov
+			}
+			if iNdEx >= l {
+				return io.ErrUnexpectedEOF
+			}
+			b := dAtA[iNdEx]
+			iNdEx++
+			wire |= uint64(b&0x7F) << shift
+			if b < 0x80 {
+				break
+			}
+		}
+		fieldNum := int32(wire >> 3)
+		wireType := int(wire & 0x7)
+		if wireType == 4 {
+			return fmt.Errorf("proto: Vote: wiretype end group for non-group")
+		}
+		if fieldNum <= 0 {
+			return fmt.Errorf("proto: Vote: illegal tag %d (wire type %d)", fieldNum, wire)
+		}
+		switch fieldNum {
+		case 1:
+			if wireType != 0 {
+				return fmt.Errorf("proto: wrong wireType = %d for field ProposalId", wireType)
+			}
+			m.ProposalId = 0
+			for shift := uint(0); ; shift += 7 {
+				if shift >= 64 {
+					return ErrIntOverflowGov
+				}
+				if iNdEx >= l {
+					return io.ErrUnexpectedEOF
+				}
+				b := dAtA[iNdEx]
+				iNdEx++
+				m.ProposalId |= uint64(b&0x7F) << shift
+				if b < 0x80 {
+					break
+				}
+			}
+		case 2:
+			if wireType != 2 {
+				return fmt.Errorf("proto: wrong wireType = %d for field Voter", wireType)
+			}
+			var stringLen uint64
+			for shift := uint(0); ; shift += 7 {
+				if shift >= 64 {
+					return ErrIntOverflowGov
+				}
+				if iNdEx >= l {
+					return io.ErrUnexpectedEOF
+				}
+				b := dAtA[iNdEx]
+				iNdEx++
+				stringLen |= uint64(b&0x7F) << shift
+				if b < 0x80 {
+					break
+				}
+			}
+			intStringLen := int(stringLen)
+			if intStringLen < 0 {
+				return ErrInvalidLengthGov
+			}
+			postIndex := iNdEx + intStringLen
+			if postIndex < 0 {
+				return ErrInvalidLengthGov
+			}
+			if postIndex > l {
+				return io.ErrUnexpectedEOF
+			}
+			m.Voter = string(dAtA[iNdEx:postIndex])
+			iNdEx = postIndex
+		case 3:
+			if wireType != 0 {
+				return fmt.Errorf("proto: wrong wireType = %d for field Option", wireType)
+			}
+			m.Option = 0
+			for shift := uint(0); ; shift += 7 {
+				if shift >= 64 {
+					return ErrIntOverflowGov
+				}
+				if iNdEx >= l {
+					return io.ErrUnexpectedEOF
+				}
+				b := dAtA[iNdEx]
+				iNdEx++
+				m.Option |= types.VoteOption(b&0x7F) << shift
+				if b < 0x80 {
+					break
+				}
+			}
+		default:
+			iNdEx = preIndex
+			skippy, err := skipGov(dAtA[iNdEx:])
+			if err != nil {
+				return err
+			}
+			if (skippy < 0) || (iNdEx+skippy) < 0 {
+				return ErrInvalidLengthGov
+			}
+			if (iNdEx + skippy) > l {
+				return io.ErrUnexpectedEOF
+			}
+			iNdEx += skippy
+		}
+	}
+
+	if iNdEx > l {
+		return io.ErrUnexpectedEOF
+	}
+	return nil
+}
+
+func skipGov(dAtA []byte) (n int, err error) {
+	l := len(dAtA)
+	iNdEx := 0
+	depth := 0
+	for iNdEx < l {
+		var wire uint64
+		for shift := uint(0); ; shift += 7 {
+			if shift >= 64 {
+				return 0, ErrIntOverflowGov
+			}
+			if iNdEx >= l {
+				return 0, io.ErrUnexpectedEOF
+			}
+			b := dAtA[iNdEx]
+			iNdEx++
+			wire |= (uint64(b) & 0x7F) << shift
+			if b < 0x80 {
+				break
+			}
+		}
+		wireType := int(wire & 0x7)
+		switch wireType {
+		case 0:
+			for shift := uint(0); ; shift += 7 {
+				if shift >= 64 {
+					return 0, ErrIntOverflowGov
+				}
+				if iNdEx >= l {
+					return 0, io.ErrUnexpectedEOF
+				}
+				iNdEx++
+				if dAtA[iNdEx-1] < 0x80 {
+					break
+				}
+			}
+		case 1:
+			iNdEx += 8
+		case 2:
+			var length int
+			for shift := uint(0); ; shift += 7 {
+				if shift >= 64 {
+					return 0, ErrIntOverflowGov
+				}
+				if iNdEx >= l {
+					return 0, io.ErrUnexpectedEOF
+				}
+				b := dAtA[iNdEx]
+				iNdEx++
+				length |= (int(b) & 0x7F) << shift
+				if b < 0x80 {
+					break
+				}
+			}
+			if length < 0 {
+				return 0, ErrInvalidLengthGov
+			}
+			iNdEx += length
+		case 3:
+			depth++
+		case 4:
+			if depth == 0 {
+				return 0, ErrUnexpectedEndOfGroupGov
+			}
+			depth--
+		case 5:
+			iNdEx += 4
+		default:
+			return 0, fmt.Errorf("proto: illegal wireType %d", wireType)
+		}
+		if iNdEx < 0 {
+			return 0, ErrInvalidLengthGov
+		}
+		if depth == 0 {
+			return iNdEx, nil
+		}
+	}
+	return 0, io.ErrUnexpectedEOF
+}
+
+var (
+	ErrInvalidLengthGov        = fmt.Errorf("proto: negative length found during unmarshaling")
+	ErrIntOverflowGov          = fmt.Errorf("proto: integer overflow")
+	ErrUnexpectedEndOfGroupGov = fmt.Errorf("proto: unexpected end of group")
+)
diff --git a/x/gov/legacy/v040/vote.go b/x/gov/legacy/v040/vote.go
new file mode 100644
index 000000000000..59bde951070b
--- /dev/null
+++ b/x/gov/legacy/v040/vote.go
@@ -0,0 +1,78 @@
+// Package v040 is copy-pasted from:
+// https://github.com/cosmos/cosmos-sdk/blob/v0.41.1/x/gov/types/vote.go
+package v040
+
+import (
+	"fmt"
+
+	yaml "gopkg.in/yaml.v2"
+
+	sdk "github.com/cosmos/cosmos-sdk/types"
+	"github.com/cosmos/cosmos-sdk/x/gov/types"
+)
+
+// NewVote creates a new Vote instance
+//nolint:interfacer
+func NewVote(proposalID uint64, voter sdk.AccAddress, option types.VoteOption) Vote {
+	return Vote{proposalID, voter.String(), option}
+}
+
+func (v Vote) String() string {
+	out, _ := yaml.Marshal(v)
+	return string(out)
+}
+
+// Votes is a collection of Vote objects
+type Votes []Vote
+
+// Equal returns true if two slices (order-dependant) of votes are equal.
+func (v Votes) Equal(other Votes) bool {
+	if len(v) != len(other) {
+		return false
+	}
+
+	for i, vote := range v {
+		if vote.String() != other[i].String() {
+			return false
+		}
+	}
+
+	return true
+}
+
+func (v Votes) String() string {
+	if len(v) == 0 {
+		return "[]"
+	}
+	out := fmt.Sprintf("Votes for Proposal %d:", v[0].ProposalId)
+	for _, vot := range v {
+		out += fmt.Sprintf("\n  %s: %s", vot.Voter, vot.Option)
+	}
+	return out
+}
+
+// Empty returns whether a vote is empty.
+func (v Vote) Empty() bool {
+	return v.String() == Vote{}.String()
+}
+
+// VoteOptionFromString returns a VoteOption from a string. It returns an error
+// if the string is invalid.
+func VoteOptionFromString(str string) (types.VoteOption, error) {
+	option, ok := types.VoteOption_value[str]
+	if !ok {
+		return types.OptionEmpty, fmt.Errorf("'%s' is not a valid vote option", str)
+	}
+	return types.VoteOption(option), nil
+}
+
+// ValidVoteOption returns true if the vote option is valid and false otherwise.
+func ValidVoteOption(option types.VoteOption) bool {
+	if option == types.OptionYes ||
+		option == types.OptionAbstain ||
+		option == types.OptionNo ||
+		option == types.OptionNoWithVeto {
+		return true
+	}
+	return false
+}
diff --git a/x/gov/legacy/v042/store.go b/x/gov/legacy/v042/store.go
index acf824a16139..84eee997f4dd 100644
--- a/x/gov/legacy/v042/store.go
+++ b/x/gov/legacy/v042/store.go
@@ -1,10 +1,12 @@
 package v042
 
 import (
+	"github.com/cosmos/cosmos-sdk/codec"
 	"github.com/cosmos/cosmos-sdk/store/prefix"
 	sdk "github.com/cosmos/cosmos-sdk/types"
 	"github.com/cosmos/cosmos-sdk/types/address"
 	v040gov "github.com/cosmos/cosmos-sdk/x/gov/legacy/v040"
+	"github.com/cosmos/cosmos-sdk/x/gov/types"
 )
 
 const proposalIDLen = 8
@@ -30,14 +32,37 @@ func migratePrefixProposalAddress(store sdk.KVStore, prefixBz []byte) {
 	}
 }
 
+// migrateWeightedVotes migrates the ADR-037 weighted votes.
+func migrateWeightedVotes(store sdk.KVStore, cdc codec.BinaryMarshaler) error {
+	iterator := sdk.KVStorePrefixIterator(store, v040gov.VotesKeyPrefix)
+
+	defer iterator.Close()
+	for ; iterator.Valid(); iterator.Next() {
+		var oldVote v040gov.Vote
+		err := cdc.UnmarshalBinaryBare(iterator.Value(), &oldVote)
+		if err != nil {
+			return err
+		}
+
+		newVote := &types.Vote{
+			ProposalId: oldVote.ProposalId,
+			Voter:      oldVote.Voter,
+			Options:    []types.WeightedVoteOption{{Option: types.VoteOption(oldVote.Option), Weight: sdk.NewDec(1)}},
+		}
+		bz, err := cdc.MarshalBinaryBare(newVote)
+		store.Set(iterator.Key(), bz)
+	}
+
+	return nil
+}
+
 // MigrateStore performs in-place store migrations from v0.40 to v0.42. The
 // migration includes:
 //
 // - Change addresses to be length-prefixed.
-func MigrateStore(ctx sdk.Context, storeKey sdk.StoreKey) error {
+func MigrateStore(ctx sdk.Context, storeKey sdk.StoreKey, cdc codec.BinaryMarshaler) error {
 	store := ctx.KVStore(storeKey)
 	migratePrefixProposalAddress(store, v040gov.DepositsKeyPrefix)
 	migratePrefixProposalAddress(store, v040gov.VotesKeyPrefix)
-
-	return nil
+	return migrateWeightedVotes(store, cdc)
 }
diff --git a/x/gov/legacy/v042/store_test.go b/x/gov/legacy/v042/store_test.go
index 6bcb056a9c99..6eaeab7e9bcb 100644
--- a/x/gov/legacy/v042/store_test.go
+++ b/x/gov/legacy/v042/store_test.go
@@ -7,6 +7,7 @@ import (
 
 	"github.com/stretchr/testify/require"
 
+	"github.com/cosmos/cosmos-sdk/simapp"
 	"github.com/cosmos/cosmos-sdk/testutil"
 	"github.com/cosmos/cosmos-sdk/testutil/testdata"
 	sdk "github.com/cosmos/cosmos-sdk/types"
@@ -16,6 +17,7 @@ import (
 )
 
 func TestStoreMigration(t *testing.T) {
+	cdc := simapp.MakeTestEncodingConfig().Marshaler
 	govKey := sdk.NewKVStoreKey("gov")
 	ctx := testutil.DefaultContext(govKey, sdk.NewTransientStoreKey("transient_test"))
 	store := ctx.KVStore(govKey)
@@ -23,53 +25,57 @@ func TestStoreMigration(t *testing.T) {
 	_, _, addr1 := testdata.KeyTestPubAddr()
 	proposalID := uint64(6)
 	now := time.Now()
-	// Use dummy value for all keys.
-	value := []byte("foo")
+	// Use dummy value for keys where we don't test values.
+	dummyValue := []byte("foo")
+	// Use real values for votes, as we're testing weighted votes.
+	oldVote := v040gov.Vote{ProposalId: 1, Voter: "foobar", Option: types.OptionNoWithVeto}
+	oldVoteValue := cdc.MustMarshalBinaryBare(&oldVote)
+	newVote := types.Vote{ProposalId: 1, Voter: "foobar", Options: types.WeightedVoteOptions{{Option: types.OptionNoWithVeto, Weight: sdk.NewDec(1)}}}
+	newVoteValue := cdc.MustMarshalBinaryBare(&newVote)
 
 	testCases := []struct {
-		name   string
-		oldKey []byte
-		newKey []byte
+		name                               string
+		oldKey, oldValue, newKey, newValue []byte
 	}{
 		{
 			"ProposalKey",
-			v040gov.ProposalKey(proposalID),
-			types.ProposalKey(proposalID),
+			v040gov.ProposalKey(proposalID), dummyValue,
+			types.ProposalKey(proposalID), dummyValue,
 		},
 		{
 			"ActiveProposalQueue",
-			v040gov.ActiveProposalQueueKey(proposalID, now),
-			types.ActiveProposalQueueKey(proposalID, now),
+			v040gov.ActiveProposalQueueKey(proposalID, now), dummyValue,
+			types.ActiveProposalQueueKey(proposalID, now), dummyValue,
 		},
 		{
 			"InactiveProposalQueue",
-			v040gov.InactiveProposalQueueKey(proposalID, now),
-			types.InactiveProposalQueueKey(proposalID, now),
+			v040gov.InactiveProposalQueueKey(proposalID, now), dummyValue,
+			types.InactiveProposalQueueKey(proposalID, now), dummyValue,
 		},
 		{
 			"ProposalIDKey",
-			v040gov.ProposalIDKey,
-			types.ProposalIDKey,
+			v040gov.ProposalIDKey, dummyValue,
+			types.ProposalIDKey, dummyValue,
 		},
 		{
 			"DepositKey",
-			v040gov.DepositKey(proposalID, addr1),
-			types.DepositKey(proposalID, addr1),
+			v040gov.DepositKey(proposalID, addr1), dummyValue,
+			types.DepositKey(proposalID, addr1), dummyValue,
 		},
 		{
 			"VotesKeyPrefix",
-			v040gov.VoteKey(proposalID, addr1),
-			types.VoteKey(proposalID, addr1),
+			v040gov.VoteKey(proposalID, addr1), oldVoteValue,
+			types.VoteKey(proposalID, addr1), newVoteValue,
 		},
 	}
 
 	// Set all the old keys to the store
 	for _, tc := range testCases {
-		store.Set(tc.oldKey, value)
+		store.Set(tc.oldKey, tc.oldValue)
 	}
 
 	// Run migrations.
-	err := v042gov.MigrateStore(ctx, govKey)
+	err := v042gov.MigrateStore(ctx, govKey, cdc)
 	require.NoError(t, err)
 
 	// Make sure the new keys are set and old keys are deleted.
@@ -79,7 +85,7 @@ func TestStoreMigration(t *testing.T) {
 			if bytes.Compare(tc.oldKey, tc.newKey) != 0 {
 				require.Nil(t, store.Get(tc.oldKey))
 			}
-			require.Equal(t, value, store.Get(tc.newKey))
+			require.Equal(t, tc.newValue, store.Get(tc.newKey))
 		})
 	}
 }