diff --git a/x/builder/keeper/msg_server_test.go b/x/builder/keeper/msg_server_test.go
index b4c962d..09e6fa4 100644
--- a/x/builder/keeper/msg_server_test.go
+++ b/x/builder/keeper/msg_server_test.go
@@ -124,5 +124,68 @@ func (suite *KeeperTestSuite) TestMsgAuctionBid() {
 }
 
 func (suite *KeeperTestSuite) TestMsgUpdateParams() {
-	suite.T().SkipNow()
+	rng := rand.New(rand.NewSource(time.Now().Unix()))
+	account := testutils.RandomAccounts(rng, 1)[0]
+
+	testCases := []struct {
+		name string
+		msg  *types.MsgUpdateParams
+
+		pass      bool
+		passBasic bool
+	}{
+		{
+			name: "invalid proposer fee",
+			msg: &types.MsgUpdateParams{
+				Authority: suite.authorityAccount.String(),
+				Params: types.Params{
+					ProposerFee: sdk.MustNewDecFromStr("1.1"),
+				},
+			},
+			passBasic: false,
+			pass:      true,
+		},
+		{
+			name: "invalid auction fees",
+			msg: &types.MsgUpdateParams{
+				Authority: suite.authorityAccount.String(),
+				Params: types.Params{
+					ProposerFee: sdk.MustNewDecFromStr("0.1"),
+				},
+			},
+			passBasic: false,
+			pass:      true,
+		},
+		{
+			name: "invalid authority address",
+			msg: &types.MsgUpdateParams{
+				Authority: account.Address.String(),
+				Params: types.Params{
+					ProposerFee:          sdk.MustNewDecFromStr("0.1"),
+					MaxBundleSize:        2,
+					EscrowAccountAddress: suite.authorityAccount.String(),
+					MinBuyInFee:          sdk.NewInt64Coin("foo", 100),
+					MinBidIncrement:      sdk.NewInt64Coin("foo", 100),
+					ReserveFee:           sdk.NewInt64Coin("foo", 100),
+				},
+			},
+			passBasic: true,
+			pass:      false,
+		},
+	}
+
+	for _, tc := range testCases {
+		suite.Run(tc.name, func() {
+			if !tc.passBasic {
+				suite.Require().Error(tc.msg.ValidateBasic())
+			}
+
+			_, err := suite.msgServer.UpdateParams(suite.ctx, tc.msg)
+			if tc.pass {
+				suite.Require().NoError(err)
+			} else {
+				suite.Require().Error(err)
+			}
+		})
+	}
 }
diff --git a/x/builder/types/msgs_test.go b/x/builder/types/msgs_test.go
index 64f8ffa..674577f 100644
--- a/x/builder/types/msgs_test.go
+++ b/x/builder/types/msgs_test.go
@@ -125,6 +125,31 @@ func TestMsgUpdateParams(t *testing.T) {
 			},
 			expectPass: true,
 		},
+		{
+			description: "invalid message with multiple fee denoms",
+			msg: types.MsgUpdateParams{
+				Authority: sdk.AccAddress([]byte("test")).String(),
+				Params: types.Params{
+					ProposerFee:          sdk.NewDec(1),
+					EscrowAccountAddress: sdk.AccAddress([]byte("test")).String(),
+					ReserveFee:           sdk.NewCoin("test", sdk.NewInt(100)),
+					MinBidIncrement:      sdk.NewCoin("test2", sdk.NewInt(100)),
+					MinBuyInFee:          sdk.NewCoin("test3", sdk.NewInt(100)),
+				},
+			},
+			expectPass: false,
+		},
+		{
+			description: "invalid message with unset fee denoms",
+			msg: types.MsgUpdateParams{
+				Authority: sdk.AccAddress([]byte("test")).String(),
+				Params: types.Params{
+					ProposerFee:          sdk.NewDec(1),
+					EscrowAccountAddress: sdk.AccAddress([]byte("test")).String(),
+				},
+			},
+			expectPass: false,
+		},
 	}
 
 	for _, tc := range cases {
diff --git a/x/builder/types/params.go b/x/builder/types/params.go
index f3186c4..c2d64fc 100644
--- a/x/builder/types/params.go
+++ b/x/builder/types/params.go
@@ -67,6 +67,16 @@ func (p Params) Validate() error {
 		return fmt.Errorf("invalid minimum bid increment (%s)", err)
 	}
 
+	denoms := map[string]struct{}{
+		p.ReserveFee.Denom:      {},
+		p.MinBuyInFee.Denom:     {},
+		p.MinBidIncrement.Denom: {},
+	}
+
+	if len(denoms) != 1 {
+		return fmt.Errorf("mismatched auction fee denoms: minimum bid increment (%s), minimum buy-in fee (%s), reserve fee (%s)", p.MinBidIncrement, p.MinBuyInFee, p.ReserveFee)
+	}
+
 	return validateProposerFee(p.ProposerFee)
 }
 
@@ -93,7 +103,6 @@ func validateProposerFee(v sdk.Dec) error {
 }
 
 func validateEscrowAccountAddress(account string) error {
-	// If the escrow account address is set, ensure it is a valid address.
 	if _, err := sdk.AccAddressFromBech32(account); err != nil {
 		return fmt.Errorf("invalid escrow account address (%s)", err)
 	}