diff --git a/src/Unpacker.php b/src/Unpacker.php
index af6ae2afe..99b398642 100644
--- a/src/Unpacker.php
+++ b/src/Unpacker.php
@@ -18,6 +18,7 @@
 use Composer\IO\IOInterface;
 use Composer\Json\JsonFile;
 use Composer\Json\JsonManipulator;
+use Composer\Package\Link;
 use Composer\Package\Locker;
 use Composer\Package\Version\VersionSelector;
 use Composer\Plugin\PluginInterface;
@@ -60,7 +61,7 @@ public function unpack(Operation $op, Result $result = null, &$links = []): Resu
                 null === $pkg ||
                 'symfony-pack' !== $pkg->getType() ||
                 !$op->shouldUnpack() ||
-                0 === \count($pkg->getRequires()) + \count($pkg->getDevRequires())
+                0 === \count($pkg->getRequires()) + \count($pkg->getDevRequires()) + \count($pkg->getReplaces()) + \count($pkg->getProvides())
             ) {
                 $result->addRequired($package['name'].($package['version'] ? ':'.$package['version'] : ''));
 
@@ -72,6 +73,16 @@ public function unpack(Operation $op, Result $result = null, &$links = []): Resu
             }
 
             $versionSelector = null;
+
+            if (!$package['dev']) {
+                foreach ($pkg->getReplaces() as $link) {
+                    $this->addLinks($link, $links, 'replace');
+                }
+                foreach ($pkg->getProvides() as $link) {
+                    $this->addLinks($link, $links, 'provide');
+                }
+            }
+
             foreach ($pkg->getRequires() as $link) {
                 if ('php' === $link->getTarget()) {
                     continue;
@@ -106,7 +117,7 @@ public function unpack(Operation $op, Result $result = null, &$links = []): Resu
 
                 if (isset($links[$linkName])) {
                     $links[$linkName]['constraints'][] = $constraint;
-                    if ('require' === $linkType) {
+                    if ('require' === $linkType && !\in_array($links['linkName']['type'],['replace', 'provide'])) {
                         $links[$linkName]['type'] = 'require';
                     }
                 } else {
@@ -200,4 +211,20 @@ public function updateLock(Result $result, IOInterface $io): void
         }
         $this->composer->setLocker($locker);
     }
+
+
+    private function addLinks(Link $link, array &$links, string $linkType): void
+    {
+        $constraint = $link->getPrettyConstraint();
+        $constraint = substr($this->resolver->parseVersion($link->getTarget(), $constraint, false), 1) ?: $constraint;
+
+        $linkName = $link->getTarget();
+        $constraint = $this->versionParser->parseConstraints($constraint);
+
+        $links[$linkName] = [
+            'type' => $linkType,
+            'name' => $linkName,
+            'constraints' => [$constraint],
+        ];
+    }
 }
diff --git a/tests/UnpackerTest.php b/tests/UnpackerTest.php
index f9e9e4ee5..04013c0eb 100644
--- a/tests/UnpackerTest.php
+++ b/tests/UnpackerTest.php
@@ -90,4 +90,158 @@ public function testDoNotDuplicateEntry(): void
         putenv('COMPOSER='.$originalEnvComposer);
         @unlink($composerJsonPath);
     }
+
+    /**
+     * Replaces are added from the packs into the main composer.json.
+     *
+     * Context:
+     *
+     *   - There are two packs: "pack_foo" and "pack_bar"
+     *   - Both points to a package named "real"
+     *   - "pack_foo" is present in the "require" section
+     *   - "pack_bar" is present in the "replace" section
+     *
+     * Expected result:
+     *
+     *   - "real" package MUST be present ONLY in "replace" section
+     */
+    public function testReplacesAreAdded(): void
+    {
+        // Setup project
+
+        $composerJsonPath = FLEX_TEST_DIR.'/composer.json';
+
+        @mkdir(FLEX_TEST_DIR);
+        @unlink($composerJsonPath);
+        file_put_contents($composerJsonPath, '{}');
+
+        $originalEnvComposer = getenv('COMPOSER');
+        putenv('COMPOSER='.$composerJsonPath);
+
+        // Setup packages
+
+        $realPkg = new Package('real', '1.0.0', '1.0.0');
+        $realPkgLink = new Link('lorem', 'real', class_exists(MatchAllConstraint::class) ? new MatchAllConstraint() : null, 'wraps', '1.0.0');
+
+        $virtualPkgFoo = new Package('pack_foo', '1.0.0', '1.0.0');
+        $virtualPkgFoo->setType('symfony-pack');
+        $virtualPkgFoo->setRequires([$realPkgLink]);
+
+        $virtualPkgBar = new Package('pack_bar', '1.0.0', '1.0.0');
+        $virtualPkgBar->setType('symfony-pack');
+        $virtualPkgBar->setReplaces([$realPkgLink]);
+
+        $packages = [$realPkg, $virtualPkgFoo, $virtualPkgBar];
+
+        // Setup Composer
+
+        $repManager = $this->getMockBuilder(RepositoryManager::class)->disableOriginalConstructor()->getMock();
+        $repManager->expects($this->any())->method('getLocalRepository')->willReturn(new InstalledArrayRepository($packages));
+
+        $composer = new Composer();
+        $composer->setRepositoryManager($repManager);
+
+        // Unpack
+
+        $resolver = $this->getMockBuilder(PackageResolver::class)->disableOriginalConstructor()->getMock();
+
+        $unpacker = new Unpacker($composer, $resolver, false);
+
+        $operation = new Operation(true, false);
+        $operation->addPackage('pack_foo', '*', false);
+        $operation->addPackage('pack_bar', '*', false);
+
+        $unpacker->unpack($operation);
+
+        // Check
+
+        $composerJson = json_decode(file_get_contents($composerJsonPath), true);
+
+        $this->assertArrayHasKey('replace', $composerJson);
+        $this->assertArrayHasKey('real', $composerJson['replace']);
+        $this->assertArrayNotHasKey('require-dev', $composerJson);
+        $this->assertArrayNotHasKey('require', $composerJson);
+
+        // Restore
+
+        putenv('COMPOSER='.$originalEnvComposer);
+        @unlink($composerJsonPath);
+    }
+
+    /**
+     * Replaces from dev dependencies are not added.
+     *
+     * Context:
+     *
+     *   - There are two packs: "pack_foo" and "pack_bar"
+     *   - Both points to a package named "real"
+     *   - "pack_foo" is present in the "require" section
+     *   - "pack_bar" is present in the "replace" section
+     *
+     * Expected result:
+     *
+     *   - "real" package MUST be present ONLY in "require" section
+     */
+    public function testReplacesAreNotAddedForDevDependencies(): void
+    {
+        // Setup project
+
+        $composerJsonPath = FLEX_TEST_DIR.'/composer.json';
+
+        @mkdir(FLEX_TEST_DIR);
+        @unlink($composerJsonPath);
+        file_put_contents($composerJsonPath, '{}');
+
+        $originalEnvComposer = getenv('COMPOSER');
+        putenv('COMPOSER='.$composerJsonPath);
+
+        // Setup packages
+
+        $realPkg = new Package('real', '1.0.0', '1.0.0');
+        $realPkgLink = new Link('lorem', 'real', class_exists(MatchAllConstraint::class) ? new MatchAllConstraint() : null, 'wraps', '1.0.0');
+
+        $virtualPkgFoo = new Package('pack_foo', '1.0.0', '1.0.0');
+        $virtualPkgFoo->setType('symfony-pack');
+        $virtualPkgFoo->setRequires([$realPkgLink]);
+
+        $virtualPkgBar = new Package('pack_bar', '1.0.0', '1.0.0');
+        $virtualPkgBar->setType('symfony-pack');
+        $virtualPkgBar->setReplaces([$realPkgLink]);
+
+        $packages = [$realPkg, $virtualPkgFoo, $virtualPkgBar];
+
+        // Setup Composer
+
+        $repManager = $this->getMockBuilder(RepositoryManager::class)->disableOriginalConstructor()->getMock();
+        $repManager->expects($this->any())->method('getLocalRepository')->willReturn(new InstalledArrayRepository($packages));
+
+        $composer = new Composer();
+        $composer->setRepositoryManager($repManager);
+
+        // Unpack
+
+        $resolver = $this->getMockBuilder(PackageResolver::class)->disableOriginalConstructor()->getMock();
+
+        $unpacker = new Unpacker($composer, $resolver, false);
+
+        $operation = new Operation(true, false);
+        $operation->addPackage('pack_foo', '*', false);
+        $operation->addPackage('pack_bar', '*', true);
+
+        $unpacker->unpack($operation);
+
+        // Check
+
+        $composerJson = json_decode(file_get_contents($composerJsonPath), true);
+
+        $this->assertArrayHasKey('require', $composerJson);
+        $this->assertArrayHasKey('real', $composerJson['require']);
+        $this->assertArrayNotHasKey('require-dev', $composerJson);
+        $this->assertArrayNotHasKey('replace', $composerJson);
+
+        // Restore
+
+        putenv('COMPOSER='.$originalEnvComposer);
+        @unlink($composerJsonPath);
+    }
 }