diff --git a/src/Composer/Package/Loader/ValidatingArrayLoader.php b/src/Composer/Package/Loader/ValidatingArrayLoader.php
index e5d513c41..7e4318b85 100644
--- a/src/Composer/Package/Loader/ValidatingArrayLoader.php
+++ b/src/Composer/Package/Loader/ValidatingArrayLoader.php
@@ -252,6 +252,7 @@ class ValidatingArrayLoader implements LoaderInterface
         foreach (array_keys(BasePackage::$supportedLinkTypes) as $linkType) {
             if ($this->validateArray($linkType) && isset($this->config[$linkType])) {
                 foreach ($this->config[$linkType] as $package => $constraint) {
+                    $package = (string) $package;
                     if (0 === strcasecmp($package, $this->config['name'])) {
                         $this->errors[] = $linkType.'.'.$package.' : a package cannot set a '.$linkType.' on itself';
                         unset($this->config[$linkType][$package]);
diff --git a/src/Composer/Package/RootPackageInterface.php b/src/Composer/Package/RootPackageInterface.php
index ad1828570..ef1ab7549 100644
--- a/src/Composer/Package/RootPackageInterface.php
+++ b/src/Composer/Package/RootPackageInterface.php
@@ -115,15 +115,6 @@ interface RootPackageInterface extends CompletePackageInterface
      */
     public function setReplaces(array $replaces): void;
 
-    /**
-     * Set the repositories
-     *
-     * @param mixed[] $repositories
-     *
-     * @return void
-     */
-    public function setRepositories(array $repositories): void;
-
     /**
      * Set the autoload mapping
      *
diff --git a/tests/Composer/Test/Package/Loader/ValidatingArrayLoaderTest.php b/tests/Composer/Test/Package/Loader/ValidatingArrayLoaderTest.php
index e3d6103e1..4562a2702 100644
--- a/tests/Composer/Test/Package/Loader/ValidatingArrayLoaderTest.php
+++ b/tests/Composer/Test/Package/Loader/ValidatingArrayLoaderTest.php
@@ -419,6 +419,13 @@ class ValidatingArrayLoaderTest extends TestCase
                     'dist.url : must be present',
                 ),
             ),
+            array(
+                array(
+                    'name' => 'foo/bar',
+                    'replace' => array('acme/bar'),
+                ),
+                array('replace.0 : invalid version constraint (Could not parse version constraint acme/bar: Invalid version string "acme/bar")')
+            ),
         ));
     }