diff --git a/modules/apps/29-fee/ibc_middleware_test.go b/modules/apps/29-fee/ibc_middleware_test.go
index 1a6a8360a78..7a388ac1748 100644
--- a/modules/apps/29-fee/ibc_middleware_test.go
+++ b/modules/apps/29-fee/ibc_middleware_test.go
@@ -1557,17 +1557,17 @@ func (suite *FeeTestSuite) TestAckUnmarshal() {
 	testCases := []struct {
 		name     string
 		ackBytes []byte
-		expPass  bool
+		expError error
 	}{
 		{
 			"success",
 			[]byte(`{"app_acknowledgement": "eyJyZXN1bHQiOiJiVzlqYXlCaFkydHViM2RzWldsblpXMWxiblE9In0=", "forward_relayer_address": "relayer", "underlying_app_success": true}`),
-			true,
+			nil,
 		},
 		{
 			"failure: unknown fields",
 			[]byte(`{"app_acknowledgement": "eyJyZXN1bHQiOiJiVzlqYXlCaFkydHViM2RzWldsblpXMWxiblE9In0=", "forward_relayer_address": "relayer", "underlying_app_success": true, "extra_field": "foo"}`),
-			false,
+			errors.New("json: unknown field \"extra_field\""),
 		},
 	}
 	for _, tc := range testCases {
@@ -1575,10 +1575,10 @@ func (suite *FeeTestSuite) TestAckUnmarshal() {
 			ack := &types.IncentivizedAcknowledgement{}
 			err := json.Unmarshal(tc.ackBytes, ack)
 
-			if tc.expPass {
+			if tc.expError == nil {
 				suite.Require().NoError(err)
 			} else {
-				suite.Require().Error(err)
+				suite.Require().ErrorContains(err, tc.expError.Error())
 			}
 		})
 	}