diff --git a/src/Composer/Command/InstallCommand.php b/src/Composer/Command/InstallCommand.php
index e2dcb6a38..937393a1c 100644
--- a/src/Composer/Command/InstallCommand.php
+++ b/src/Composer/Command/InstallCommand.php
@@ -232,8 +232,8 @@ EOT
                     }
                     if ($package && $package->isDev()) {
                         foreach ($composer->getLocker()->getLockedPackages() as $lockedPackage) {
-                            if (!empty($lockedPackage['source_reference']) && strtolower($lockedPackage['package']) === $package->getName()) {
-                                $package->setSourceReference($lockedPackage['source_reference']);
+                            if (!empty($lockedPackage['source-reference']) && strtolower($lockedPackage['package']) === $package->getName()) {
+                                $package->setSourceReference($lockedPackage['source-reference']);
                             }
                         }
                     }
diff --git a/src/Composer/Package/Locker.php b/src/Composer/Package/Locker.php
index 39a299873..255835ec3 100644
--- a/src/Composer/Package/Locker.php
+++ b/src/Composer/Package/Locker.php
@@ -119,7 +119,7 @@ class Locker
             $spec = array('package' => $name, 'version' => $version);
 
             if ($package->isDev()) {
-                $spec['source_reference'] = $package->getSourceReference();
+                $spec['source-reference'] = $package->getSourceReference();
             }
 
             $lock['packages'][] = $spec;