diff --git a/src/Composer/Installer.php b/src/Composer/Installer.php
index 270c75544..a0e365ded 100644
--- a/src/Composer/Installer.php
+++ b/src/Composer/Installer.php
@@ -313,15 +313,6 @@ class Installer
             }
         }
 
-        if ($this->update) {
-            $vendorDir = $this->config->get('vendor-dir');
-            if (is_dir($vendorDir)) {
-                // suppress errors as this fails sometimes on OSX for no apparent reason
-                // see https://github.com/composer/composer/issues/4070#issuecomment-129792748
-                @touch($vendorDir);
-            }
-        }
-
         if ($this->runScripts) {
             // dispatch post event
             $eventName = $this->update ? ScriptEvents::POST_UPDATE_CMD : ScriptEvents::POST_INSTALL_CMD;
@@ -633,6 +624,15 @@ class Installer
             $localRepo->write();
         }
 
+        if ($operations) {
+            $vendorDir = $this->config->get('vendor-dir');
+            if (is_dir($vendorDir)) {
+                // suppress errors as this fails sometimes on OSX for no apparent reason
+                // see https://github.com/composer/composer/issues/4070#issuecomment-129792748
+                @touch($vendorDir);
+            }
+        }
+
         return array(0, $devPackages);
     }