diff --git a/internal/endtoend/testdata/params_duplicate/mysql/go/models.go b/internal/endtoend/testdata/params_duplicate/mysql/go/models.go
index 4222f42b1b..ec72cdf8ec 100644
--- a/internal/endtoend/testdata/params_duplicate/mysql/go/models.go
+++ b/internal/endtoend/testdata/params_duplicate/mysql/go/models.go
@@ -8,6 +8,6 @@ import (
 
 type User struct {
 	ID        int32
-	FirstName string
+	FirstName sql.NullString
 	LastName  sql.NullString
 }
diff --git a/internal/endtoend/testdata/params_duplicate/mysql/go/query.sql.go b/internal/endtoend/testdata/params_duplicate/mysql/go/query.sql.go
index e61cd018c6..1f48521520 100644
--- a/internal/endtoend/testdata/params_duplicate/mysql/go/query.sql.go
+++ b/internal/endtoend/testdata/params_duplicate/mysql/go/query.sql.go
@@ -5,22 +5,63 @@ package querytest
 
 import (
 	"context"
+	"database/sql"
 )
 
-const selectUserArg = `-- name: SelectUserArg :many
+const selectUserByID = `-- name: SelectUserByID :many
 SELECT first_name from
 users where (? = id OR ? = 0)
 `
 
-func (q *Queries) SelectUserArg(ctx context.Context, id interface{}) ([]string, error) {
-	rows, err := q.db.QueryContext(ctx, selectUserArg, id)
+type SelectUserByIDParams struct {
+	Column1 interface{}
+	ID      interface{}
+}
+
+func (q *Queries) SelectUserByID(ctx context.Context, arg SelectUserByIDParams) ([]sql.NullString, error) {
+	rows, err := q.db.QueryContext(ctx, selectUserByID, arg.Column1, arg.ID)
+	if err != nil {
+		return nil, err
+	}
+	defer rows.Close()
+	var items []sql.NullString
+	for rows.Next() {
+		var first_name sql.NullString
+		if err := rows.Scan(&first_name); err != nil {
+			return nil, err
+		}
+		items = append(items, first_name)
+	}
+	if err := rows.Close(); err != nil {
+		return nil, err
+	}
+	if err := rows.Err(); err != nil {
+		return nil, err
+	}
+	return items, nil
+}
+
+const selectUserByName = `-- name: SelectUserByName :many
+SELECT first_name
+FROM users
+WHERE first_name = ?
+   OR last_name = ?
+`
+
+type SelectUserByNameParams struct {
+	FirstName sql.NullString
+	Name      sql.NullString
+}
+
+func (q *Queries) SelectUserByName(ctx context.Context, arg SelectUserByNameParams) ([]sql.NullString, error) {
+	rows, err := q.db.QueryContext(ctx, selectUserByName, arg.FirstName, arg.Name)
 	if err != nil {
 		return nil, err
 	}
 	defer rows.Close()
-	var items []string
+	var items []sql.NullString
 	for rows.Next() {
-		var first_name string
+		var first_name sql.NullString
 		if err := rows.Scan(&first_name); err != nil {
 			return nil, err
 		}
@@ -45,15 +86,15 @@ type SelectUserQuestionParams struct {
 	Column2 interface{}
 }
 
-func (q *Queries) SelectUserQuestion(ctx context.Context, arg SelectUserQuestionParams) ([]string, error) {
+func (q *Queries) SelectUserQuestion(ctx context.Context, arg SelectUserQuestionParams) ([]sql.NullString, error) {
 	rows, err := q.db.QueryContext(ctx, selectUserQuestion, arg.Column1, arg.Column2)
 	if err != nil {
 		return nil, err
 	}
 	defer rows.Close()
-	var items []string
+	var items []sql.NullString
 	for rows.Next() {
-		var first_name string
+		var first_name sql.NullString
 		if err := rows.Scan(&first_name); err != nil {
 			return nil, err
 		}
diff --git a/internal/endtoend/testdata/params_duplicate/mysql/query.sql b/internal/endtoend/testdata/params_duplicate/mysql/query.sql
index 5f1a4711f6..cd661993c7 100644
--- a/internal/endtoend/testdata/params_duplicate/mysql/query.sql
+++ b/internal/endtoend/testdata/params_duplicate/mysql/query.sql
@@ -1,7 +1,13 @@
-/* name: SelectUserArg :many */
+/* name: SelectUserByID :many */
 SELECT first_name from
 users where (sqlc.arg(id) = id OR sqlc.arg(id) = 0);
 
+/* name: SelectUserByName :many */
+SELECT first_name
+FROM users
+WHERE first_name = sqlc.arg(name)
+   OR last_name = sqlc.arg(name);
+
 /* name: SelectUserQuestion :many */
 SELECT first_name from
 users where (? = id OR  ? = 0);
diff --git a/internal/endtoend/testdata/params_duplicate/mysql/schema.sql b/internal/endtoend/testdata/params_duplicate/mysql/schema.sql
index 015e792e7e..e93e087e50 100644
--- a/internal/endtoend/testdata/params_duplicate/mysql/schema.sql
+++ b/internal/endtoend/testdata/params_duplicate/mysql/schema.sql
@@ -1,5 +1,5 @@
 CREATE TABLE users (
     id integer NOT NULL AUTO_INCREMENT PRIMARY KEY,
-    first_name varchar(255) NOT NULL,
+    first_name varchar(255),
     last_name varchar(255)
 ) ENGINE=InnoDB;
diff --git a/internal/sql/rewrite/parameters.go b/internal/sql/rewrite/parameters.go
index 87a5fb07cb..7c79e9b6d9 100644
--- a/internal/sql/rewrite/parameters.go
+++ b/internal/sql/rewrite/parameters.go
@@ -48,6 +48,8 @@ func NamedParameters(engine config.Engine, raw *ast.RawStmt) (*ast.RawStmt, map[
 		return raw, map[int]string{}, nil
 	}
 
+	hasNamedParameterSupport := engine != config.EngineMySQL
+
 	args := map[string]int{}
 	argn := 0
 	var edits []source.Edit
@@ -58,7 +60,7 @@ func NamedParameters(engine config.Engine, raw *ast.RawStmt) (*ast.RawStmt, map[
 		case named.IsParamFunc(node):
 			fun := node.(*ast.FuncCall)
 			param, isConst := flatten(fun.Args)
-			if num, ok := args[param]; ok {
+			if num, ok := args[param]; ok && hasNamedParameterSupport {
 				cr.Replace(&ast.ParamRef{
 					Number:   num,
 					Location: fun.Location,