diff --git a/alwaysencrypted_test.go b/alwaysencrypted_test.go
index 18c77997..9dd08b59 100644
--- a/alwaysencrypted_test.go
+++ b/alwaysencrypted_test.go
@@ -67,7 +67,9 @@ func TestAlwaysEncryptedE2E(t *testing.T) {
 		{"datetime2(7)", "DATETIME2", ColumnEncryptionDeterministic, civil.DateTimeOf(dt)},
 		{"nvarchar(max)", "NVARCHAR", ColumnEncryptionRandomized, NVarCharMax("nvarcharmaxval")},
 		{"int", "INT", ColumnEncryptionDeterministic, sql.NullInt32{Valid: false}},
-		{"int", "INT", ColumnEncryptionDeterministic, sql.NullInt64{Int64: 128, Valid: true}},
+		{"bigint", "BIGINT", ColumnEncryptionDeterministic, sql.NullInt64{Int64: 128, Valid: true}},
+		{"uniqueidentifier", "UNIQUEIDENTIFIER", ColumnEncryptionRandomized, UniqueIdentifier{0x01, 0x23, 0x45, 0x67, 0x89, 0xAB, 0xCD, 0xEF, 0x01, 0x23, 0x45, 0x67, 0x89, 0xAB, 0xCD, 0xEF}},
+		{"uniqueidentifier", "UNIQUEIDENTIFIER", ColumnEncryptionRandomized, NullUniqueIdentifier{Valid: false}},
 	}
 	for _, test := range providerTests {
 		// turn off key caching
@@ -231,8 +233,6 @@ func comparisonValueFromObject(object interface{}) string {
 	case time.Time:
 		return civil.DateTimeOf(v).String()
 		//return v.Format(time.RFC3339)
-	case fmt.Stringer:
-		return v.String()
 	case bool:
 		if v == true {
 			return "1"
@@ -244,6 +244,8 @@ func comparisonValueFromObject(object interface{}) string {
 			return "<nil>"
 		}
 		return comparisonValueFromObject(val)
+	case fmt.Stringer:
+		return v.String()
 	default:
 		return fmt.Sprintf("%v", v)
 	}
diff --git a/mssql.go b/mssql.go
index 9238ff60..f86d5361 100644
--- a/mssql.go
+++ b/mssql.go
@@ -982,8 +982,13 @@ func (s *Stmt) makeParam(val driver.Value) (res param, err error) {
 		res.ti.Size = 0
 		return
 	}
-	// If the value has a non-nil value, call MakeParam on its Value
-	if valuer, ok := val.(driver.Valuer); ok {
+	switch valuer := val.(type) {
+	case UniqueIdentifier:
+	case NullUniqueIdentifier:
+	default:
+		break
+	case driver.Valuer:
+		// If the value has a non-nil value, call MakeParam on its Value
 		val, e := driver.DefaultParameterConverter.ConvertValue(valuer)
 		if e != nil {
 			err = e
@@ -994,6 +999,20 @@ func (s *Stmt) makeParam(val driver.Value) (res param, err error) {
 		}
 	}
 	switch val := val.(type) {
+	case UniqueIdentifier:
+		res.ti.TypeId = typeGuid
+		res.ti.Size = 16
+		guid, _ := val.Value()
+		res.buffer = guid.([]byte)
+	case NullUniqueIdentifier:
+		res.ti.TypeId = typeGuid
+		res.ti.Size = 16
+		if val.Valid {
+			guid, _ := val.Value()
+			res.buffer = guid.([]byte)
+		} else {
+			res.buffer = []byte{}
+		}
 	case int:
 		res.ti.TypeId = typeIntN
 		// Rather than guess if the caller intends to pass a 32bit int from a 64bit app based on the
diff --git a/mssql_go19.go b/mssql_go19.go
index b0285eef..6435f67e 100644
--- a/mssql_go19.go
+++ b/mssql_go19.go
@@ -75,6 +75,8 @@ func convertInputParameter(val interface{}) (interface{}, error) {
 	// 	return nil
 	case float32:
 		return val, nil
+	case driver.Valuer:
+		return val, nil
 	default:
 		return driver.DefaultParameterConverter.ConvertValue(v)
 	}