diff --git a/src/Prettus/Repository/Criteria/RequestCriteria.php b/src/Prettus/Repository/Criteria/RequestCriteria.php
index 40fc304a..b8d63436 100644
--- a/src/Prettus/Repository/Criteria/RequestCriteria.php
+++ b/src/Prettus/Repository/Criteria/RequestCriteria.php
@@ -4,6 +4,7 @@
 use Illuminate\Database\Eloquent\Builder;
 use Illuminate\Database\Eloquent\Model;
 use Illuminate\Http\Request;
+use Illuminate\Support\Str;
 use Prettus\Repository\Contracts\CriteriaInterface;
 use Prettus\Repository\Contracts\RepositoryInterface;
 
@@ -136,7 +137,7 @@ public function apply($model, RepositoryInterface $repository)
                      * ex.
                      * products -> product_id
                      */
-                    $prefix = str_singular($sortTable);
+                    $prefix = Str::singular($sortTable);
                     $keyName = $table.'.'.$prefix.'_id';
                 }
 
diff --git a/src/Prettus/Repository/Generators/Commands/RepositoryCommand.php b/src/Prettus/Repository/Generators/Commands/RepositoryCommand.php
index 2d0a0aa9..012f88c8 100644
--- a/src/Prettus/Repository/Generators/Commands/RepositoryCommand.php
+++ b/src/Prettus/Repository/Generators/Commands/RepositoryCommand.php
@@ -3,6 +3,7 @@
 
 use Illuminate\Console\Command;
 use Illuminate\Support\Collection;
+use Illuminate\Support\Str;
 use Prettus\Repository\Generators\FileAlreadyExistsException;
 use Prettus\Repository\Generators\MigrationGenerator;
 use Prettus\Repository\Generators\ModelGenerator;
@@ -66,7 +67,7 @@ public function fire()
         $this->generators = new Collection();
 
         $migrationGenerator = new MigrationGenerator([
-            'name'   => 'create_' . snake_case(str_plural($this->argument('name'))) . '_table',
+            'name'   => 'create_' . Str::snake(Str::plural($this->argument('name'))) . '_table',
             'fields' => $this->option('fillable'),
             'force'  => $this->option('force'),
         ]);
diff --git a/src/Prettus/Repository/Generators/ControllerGenerator.php b/src/Prettus/Repository/Generators/ControllerGenerator.php
index b3377cb5..b9385977 100644
--- a/src/Prettus/Repository/Generators/ControllerGenerator.php
+++ b/src/Prettus/Repository/Generators/ControllerGenerator.php
@@ -1,6 +1,8 @@
 <?php
 namespace Prettus\Repository\Generators;
 
+use Illuminate\Support\Str;
+
 /**
  * Class ControllerGenerator
  * @package Prettus\Repository\Generators
@@ -75,7 +77,7 @@ public function getControllerName()
     public function getPluralName()
     {
 
-        return str_plural(lcfirst(ucwords($this->getClass())));
+        return Str::plural(lcfirst(ucwords($this->getClass())));
     }
 
     /**
@@ -103,7 +105,7 @@ public function getReplacements()
      */
     public function getSingularName()
     {
-        return str_singular(lcfirst(ucwords($this->getClass())));
+        return Str::singular(lcfirst(ucwords($this->getClass())));
     }
 
     /**
diff --git a/src/Prettus/Repository/Generators/Generator.php b/src/Prettus/Repository/Generators/Generator.php
index e6192922..afc42096 100644
--- a/src/Prettus/Repository/Generators/Generator.php
+++ b/src/Prettus/Repository/Generators/Generator.php
@@ -135,10 +135,10 @@ public function getPath()
     public function getName()
     {
         $name = $this->name;
-        if (str_contains($this->name, '\\')) {
+        if (Str::contains($this->name, '\\')) {
             $name = str_replace('\\', '/', $this->name);
         }
-        if (str_contains($this->name, '/')) {
+        if (Str::contains($this->name, '/')) {
             $name = str_replace('/', '/', $this->name);
         }
 
diff --git a/src/Prettus/Repository/Generators/Migrations/RulesParser.php b/src/Prettus/Repository/Generators/Migrations/RulesParser.php
index 1bda2694..72637646 100644
--- a/src/Prettus/Repository/Generators/Migrations/RulesParser.php
+++ b/src/Prettus/Repository/Generators/Migrations/RulesParser.php
@@ -2,6 +2,7 @@
 namespace Prettus\Repository\Generators\Migrations;
 
 use Illuminate\Contracts\Support\Arrayable;
+use Illuminate\Support\Arr;
 
 /**
  * Class RulesParser
@@ -82,7 +83,7 @@ public function getRules()
      */
     public function getColumn($rules)
     {
-        return array_first(explode('=>', $rules), function ($key, $value) {
+        return Arr::first(explode('=>', $rules), function ($key, $value) {
             return $value;
         });
     }
diff --git a/src/Prettus/Repository/Generators/Migrations/SchemaParser.php b/src/Prettus/Repository/Generators/Migrations/SchemaParser.php
index a9270968..c97c49ec 100644
--- a/src/Prettus/Repository/Generators/Migrations/SchemaParser.php
+++ b/src/Prettus/Repository/Generators/Migrations/SchemaParser.php
@@ -2,6 +2,8 @@
 namespace Prettus\Repository\Generators\Migrations;
 
 use Illuminate\Contracts\Support\Arrayable;
+use Illuminate\Support\Arr;
+use Illuminate\Support\Str;
 
 /**
  * Class SchemaParser
@@ -114,7 +116,7 @@ public function getSchemas()
      */
     public function getColumn($schema)
     {
-        return array_first(explode(':', $schema), function ($key, $value) {
+        return Arr::first(explode(':', $schema), function ($key, $value) {
             return $value;
         });
     }
@@ -208,7 +210,7 @@ protected function addColumn($key, $field, $column)
         if ($key == 0) {
             return '->' . $field . "('" . $column . "')";
         }
-        if (str_contains($field, '(')) {
+        if (Str::contains($field, '(')) {
             return '->' . $field;
         }