diff --git a/protocol/lib/ante/nested_msg.go b/protocol/lib/ante/nested_msg.go
index db2a09ec77..cf3cd6433f 100644
--- a/protocol/lib/ante/nested_msg.go
+++ b/protocol/lib/ante/nested_msg.go
@@ -12,6 +12,7 @@ import (
 )
 
 const DYDX_MSG_PREFIX = "/" + constants.AppName
+const CONNECT_MSG_PREFIX = "/connect"
 
 // IsNestedMsg returns true if the given msg is a nested msg.
 func IsNestedMsg(msg sdk.Msg) bool {
@@ -32,6 +33,11 @@ func IsDydxMsg(msg sdk.Msg) bool {
 	return strings.HasPrefix(sdk.MsgTypeURL(msg), DYDX_MSG_PREFIX)
 }
 
+// IsConnectMsg returns true if the given msg is a Connect custom msg.
+func IsConnectMsg(msg sdk.Msg) bool {
+	return strings.HasPrefix(sdk.MsgTypeURL(msg), CONNECT_MSG_PREFIX)
+}
+
 // ValidateNestedMsg returns err if the given msg is an invalid nested msg.
 func ValidateNestedMsg(msg sdk.Msg) error {
 	if !IsNestedMsg(msg) {
@@ -80,6 +86,9 @@ func validateInnerMsg(msg sdk.Msg) error {
 			if IsDydxMsg(inner) {
 				return fmt.Errorf("Invalid nested msg for MsgExec: dydx msg type")
 			}
+			if IsConnectMsg(inner) {
+				return fmt.Errorf("Invalid nested msg for MsgExec: Connect msg type")
+			}
 		}
 
 		// For "internal msgs", we allow them, because they are designed to be nested.
diff --git a/protocol/lib/ante/nested_msg_test.go b/protocol/lib/ante/nested_msg_test.go
index 94ffe95c58..0a98a94b84 100644
--- a/protocol/lib/ante/nested_msg_test.go
+++ b/protocol/lib/ante/nested_msg_test.go
@@ -22,6 +22,7 @@ var (
 	invalidInnerMsgErr_AppInjected = fmt.Errorf("Invalid nested msg: app-injected msg type")
 	invalidInnerMsgErr_Nested      = fmt.Errorf("Invalid nested msg: double-nested msg type")
 	invalidInnerMsgErr_Dydx        = fmt.Errorf("Invalid nested msg for MsgExec: dydx msg type")
+	invalidInnerMsgErr_Connect     = fmt.Errorf("Invalid nested msg for MsgExec: Connect msg type")
 )
 
 func TestIsNestedMsg_Empty(t *testing.T) {
@@ -106,6 +107,36 @@ func TestIsDydxMsg_Valid(t *testing.T) {
 	}
 }
 
+func TestIsConnectMsg_Invalid(t *testing.T) {
+	allConnectMsgs := lib.MergeAllMapsMustHaveDistinctKeys(
+		appmsgs.NormalMsgsConnect,
+	)
+	allMsgsMinusConnect := lib.MergeAllMapsMustHaveDistinctKeys(appmsgs.AllowMsgs, appmsgs.DisallowMsgs)
+	for key := range allConnectMsgs {
+		delete(allMsgsMinusConnect, key)
+	}
+	allNonNilSampleMsgs := testmsgs.GetNonNilSampleMsgs(allMsgsMinusConnect)
+
+	for _, sampleMsg := range allNonNilSampleMsgs {
+		t.Run(sampleMsg.Name, func(t *testing.T) {
+			require.False(t, ante.IsConnectMsg(sampleMsg.Msg))
+		})
+	}
+}
+
+func TestIsConnectMsg_Valid(t *testing.T) {
+	allConnectMsgs := lib.MergeAllMapsMustHaveDistinctKeys(
+		appmsgs.NormalMsgsConnect,
+	)
+	allNonNilSampleMsgs := testmsgs.GetNonNilSampleMsgs(allConnectMsgs)
+
+	for _, sampleMsg := range allNonNilSampleMsgs {
+		t.Run(sampleMsg.Name, func(t *testing.T) {
+			require.True(t, ante.IsConnectMsg(sampleMsg.Msg))
+		})
+	}
+}
+
 func TestValidateNestedMsg(t *testing.T) {
 	tests := map[string]struct {
 		msg         sdk.Msg
@@ -143,6 +174,10 @@ func TestValidateNestedMsg(t *testing.T) {
 			msg:         &testmsgs.MsgExecWithDydxMessage,
 			expectedErr: invalidInnerMsgErr_Dydx,
 		},
+		"Invalid MsgExec: Connect custom msg": {
+			msg:         &testmsgs.MsgExecWithConnectMessage,
+			expectedErr: invalidInnerMsgErr_Connect,
+		},
 		"Valid: empty inner msg": {
 			msg:         testmsgs.MsgSubmitProposalWithEmptyInner,
 			expectedErr: nil,
diff --git a/protocol/testutil/msgs/nested_msgs.go b/protocol/testutil/msgs/nested_msgs.go
index 7b4b91625f..207903bd27 100644
--- a/protocol/testutil/msgs/nested_msgs.go
+++ b/protocol/testutil/msgs/nested_msgs.go
@@ -10,6 +10,7 @@ import (
 	"github.com/dydxprotocol/v4-chain/protocol/testutil/encoding"
 	prices "github.com/dydxprotocol/v4-chain/protocol/x/prices/types"
 	sending "github.com/dydxprotocol/v4-chain/protocol/x/sending/types"
+	marketmap "github.com/skip-mev/connect/v2/x/marketmap/types"
 )
 
 func init() {
@@ -46,6 +47,9 @@ func init() {
 	_ = testTxBuilder.SetMsgs(&MsgExecWithDydxMessage)
 	MsgExecWithDydxMessageTxBytes, _ = testEncodingCfg.TxConfig.TxEncoder()(testTxBuilder.GetTx())
 
+	_ = testTxBuilder.SetMsgs(&MsgExecWithConnectMessage)
+	MsgExecWithConnectMessageTxBytes, _ = testEncodingCfg.TxConfig.TxEncoder()(testTxBuilder.GetTx())
+
 	_ = testTxBuilder.SetMsgs(MsgSubmitProposalWithUpgrade)
 	MsgSubmitProposalWithUpgradeTxBytes, _ = testEncodingCfg.TxConfig.TxEncoder()(testTxBuilder.GetTx())
 
@@ -120,6 +124,12 @@ var (
 	)
 	MsgExecWithDydxMessageTxBytes []byte
 
+	MsgExecWithConnectMessage = authz.NewMsgExec(
+		constants.AliceAccAddress,
+		[]sdk.Msg{&marketmap.MsgUpsertMarkets{}},
+	)
+	MsgExecWithConnectMessageTxBytes []byte
+
 	// Valid MsgSubmitProposals
 	MsgSubmitProposalWithUpgrade, _ = gov.NewMsgSubmitProposal(
 		[]sdk.Msg{MsgSoftwareUpgrade}, nil, testProposer, testMetadata, testTitle, testSummary, false)