diff --git a/system/Config/Factories.php b/system/Config/Factories.php
index 0eb6d2443e44..6db25549dca9 100644
--- a/system/Config/Factories.php
+++ b/system/Config/Factories.php
@@ -118,6 +118,7 @@ public static function define(string $component, string $alias, string $classnam
         self::getOptions($component);
 
         self::$aliases[$component][$alias] = $classname;
+        self::$updated[$component]         = true;
     }
 
     /**
@@ -142,6 +143,7 @@ public static function __callStatic(string $component, array $arguments)
                 return new $class(...$arguments);
             }
 
+            // Try to locate the class
             if ($class = self::locateClass($options, $alias)) {
                 return new $class(...$arguments);
             }
@@ -160,14 +162,8 @@ public static function __callStatic(string $component, array $arguments)
             return null;
         }
 
-        self::$instances[$options['component']][$class] = new $class(...$arguments);
-        self::$aliases[$options['component']][$alias]   = $class;
-        self::$updated[$options['component']]           = true;
-
-        // If a short classname is specified, also register FQCN to share the instance.
-        if (! isset(self::$aliases[$options['component']][$class])) {
-            self::$aliases[$options['component']][$class] = $class;
-        }
+        self::createInstance($options['component'], $class, $arguments);
+        self::setAlias($options['component'], $alias, $class);
 
         return self::$instances[$options['component']][$class];
     }
@@ -179,6 +175,7 @@ public static function __callStatic(string $component, array $arguments)
      */
     private static function getDefinedInstance(array $options, string $alias, array $arguments)
     {
+        // The alias is already defined.
         if (isset(self::$aliases[$options['component']][$alias])) {
             $class = self::$aliases[$options['component']][$alias];
 
@@ -189,15 +186,50 @@ private static function getDefinedInstance(array $options, string $alias, array
                     return self::$instances[$options['component']][$class];
                 }
 
-                self::$instances[$options['component']][$class] = new $class(...$arguments);
+                self::createInstance($options['component'], $class, $arguments);
 
                 return self::$instances[$options['component']][$class];
             }
         }
 
+        // Try to locate the class
+        if (! $class = self::locateClass($options, $alias)) {
+            return null;
+        }
+
+        // Check for an existing instance for the class
+        if (isset(self::$instances[$options['component']][$class])) {
+            self::setAlias($options['component'], $alias, $class);
+
+            return self::$instances[$options['component']][$class];
+        }
+
         return null;
     }
 
+    /**
+     * Creates the shared instance.
+     */
+    private static function createInstance(string $component, string $class, array $arguments): void
+    {
+        self::$instances[$component][$class] = new $class(...$arguments);
+        self::$updated[$component]           = true;
+    }
+
+    /**
+     * Sets alias
+     */
+    private static function setAlias(string $component, string $alias, string $class): void
+    {
+        self::$aliases[$component][$alias] = $class;
+        self::$updated[$component]         = true;
+
+        // If a short classname is specified, also register FQCN to share the instance.
+        if (! isset(self::$aliases[$component][$class]) && ! self::isNamespaced($alias)) {
+            self::$aliases[$component][$class] = $class;
+        }
+    }
+
     /**
      * Is the component Config?
      *
diff --git a/tests/system/Config/FactoriesTest.php b/tests/system/Config/FactoriesTest.php
index c5936a7c341f..b53c1e9133e5 100644
--- a/tests/system/Config/FactoriesTest.php
+++ b/tests/system/Config/FactoriesTest.php
@@ -12,6 +12,7 @@
 namespace CodeIgniter\Config;
 
 use CodeIgniter\Test\CIUnitTestCase;
+use Config\App;
 use Config\Database;
 use InvalidArgumentException;
 use ReflectionClass;
@@ -322,6 +323,14 @@ public function testCanLoadTwoCellsWithSameShortName()
         $this->assertNotSame($cell1, $cell2);
     }
 
+    public function testCanLoadSharedConfigWithDifferentAlias()
+    {
+        $config1 = Factories::config(App::class);
+        $config2 = Factories::config('App');
+
+        $this->assertSame($config1, $config2);
+    }
+
     public function testDefineSameAliasTwiceWithDifferentClasses()
     {
         $this->expectException(InvalidArgumentException::class);