diff --git a/src/Symfony/Component/Console/Command/Command.php b/src/Symfony/Component/Console/Command/Command.php
index 6f687d38c1084..d09c8876a7f6b 100644
--- a/src/Symfony/Component/Console/Command/Command.php
+++ b/src/Symfony/Component/Console/Command/Command.php
@@ -120,6 +120,12 @@ public function __construct(?string $name = null, ?callable $code = null)
                 $name = array_shift($aliases);
             }
 
+            // we must not overwrite existing aliases, combine new ones with existing ones
+            $aliases = array_unique([
+                ...$this->aliases,
+                ...$aliases,
+            ]);
+
             $this->setAliases($aliases);
         }
 
diff --git a/src/Symfony/Component/Console/Tests/Command/CommandTest.php b/src/Symfony/Component/Console/Tests/Command/CommandTest.php
index 3a75ea7e4a448..e56ddfbab4207 100644
--- a/src/Symfony/Component/Console/Tests/Command/CommandTest.php
+++ b/src/Symfony/Component/Console/Tests/Command/CommandTest.php
@@ -199,12 +199,25 @@ public function testGetProcessedHelp()
     public function testGetSetAliases()
     {
         $command = new \TestCommand();
-        $this->assertEquals(['name'], $command->getAliases(), '->getAliases() returns the aliases');
         $ret = $command->setAliases(['name1']);
         $this->assertEquals($command, $ret, '->setAliases() implements a fluent interface');
         $this->assertEquals(['name1'], $command->getAliases(), '->setAliases() sets the aliases');
     }
 
+    public function testAliasesSetBeforeParentConstructorArePreserved()
+    {
+        $command = new class extends Command {
+            public function __construct()
+            {
+                // set aliases before calling parent constructor
+                $this->setAliases(['existingalias']);
+                parent::__construct('foo|newalias');
+            }
+        };
+
+        $this->assertSame(['existingalias', 'newalias'], $command->getAliases(), 'Aliases set before parent::__construct() must be preserved.');
+    }
+
     #[TestWith(['name|alias1|alias2', 'name', ['alias1', 'alias2'], false])]
     #[TestWith(['|alias1|alias2', 'alias1', ['alias2'], true])]
     public function testSetAliasesAndHiddenViaName(string $name, string $expectedName, array $expectedAliases, bool $expectedHidden)