diff --git a/core/Application/Kernel/EnvironmentValidator.php b/core/Application/Kernel/EnvironmentValidator.php
index 862593a108d..5efed4b666e 100644
--- a/core/Application/Kernel/EnvironmentValidator.php
+++ b/core/Application/Kernel/EnvironmentValidator.php
@@ -77,7 +77,7 @@ private function checkConfigFileExists($path, $startInstaller = false)
 
         $message = $this->getSpecificMessageWhetherFileExistsOrNot($path);
 
-        $exception = new \Exception($message);
+        $exception = new NotYetInstalledException($message);
 
         if ($startInstaller) {
             $this->startInstallation($exception);
diff --git a/plugins/Installation/Installation.php b/plugins/Installation/Installation.php
index aa4ff1c6dfa..a1d29643437 100644
--- a/plugins/Installation/Installation.php
+++ b/plugins/Installation/Installation.php
@@ -107,8 +107,13 @@ public function dispatch($exception = null)
 
         $action = Common::getRequestVar('action', 'welcome', 'string');
 
-        if ($this->isAllowedAction($action)) {
+        if ($this->isAllowedAction($action) && (!defined('PIWIK_ENABLE_DISPATCH') || PIWIK_ENABLE_DISPATCH)) {
             echo FrontController::getInstance()->dispatch('Installation', $action, array($message));
+        } elseif (defined('PIWIK_ENABLE_DISPATCH') && !PIWIK_ENABLE_DISPATCH) {
+            if ($exception && $exception instanceof \Exception) {
+                throw $exception;
+            }
+            return;
         } else {
             Piwik::exitWithErrorMessage($this->getMessageToInviteUserToInstallPiwik($message));
         }
diff --git a/plugins/Installation/tests/System/APITest.php b/plugins/Installation/tests/System/APITest.php
index d8ae5523c8a..887e5e17ba9 100644
--- a/plugins/Installation/tests/System/APITest.php
+++ b/plugins/Installation/tests/System/APITest.php
@@ -61,6 +61,13 @@ public function test_shouldReturnValidApiResponse_IfWrongDbInfo_formatJSON()
         $this->assertContains('Access denied', $data);
     }
 
+    public function test_shouldReturnEmptyResultWhenNotInstalledAndDispatchIsDisabled()
+    {
+        $url = Fixture::getTestRootUrl() . 'nodispatchnotinstalled.php';
+        $response = $this->sendHttpRequest($url);
+        $this->assertSame('', $response['data']);
+    }
+
     private function getUrl()
     {
         return Fixture::getRootUrl() . 'tests/PHPUnit/proxy/index.php?module=API&method=API.getPiwikVersion';
diff --git a/tests/PHPUnit/proxy/nodispatchnotinstalled.php b/tests/PHPUnit/proxy/nodispatchnotinstalled.php
new file mode 100644
index 00000000000..f4fabeecf1b
--- /dev/null
+++ b/tests/PHPUnit/proxy/nodispatchnotinstalled.php
@@ -0,0 +1,20 @@
+<?php
+/**
+ * Proxy to index.php, but will use the Test DB
+ * Used by tests/PHPUnit/System/ImportLogsTest.php and tests/PHPUnit/System/UITest.php
+ */
+
+use Piwik\Application\Environment;
+use Piwik\Tests\Framework\TestingEnvironmentManipulator;
+use Piwik\Tests\Framework\TestingEnvironmentVariables;
+
+define('PIWIK_ENABLE_DISPATCH', false);
+
+require realpath(dirname(__FILE__)) . "/includes.php";
+$testEnvironment = new TestingEnvironmentVariables();
+$testEnvironment->configFileLocal = PIWIK_INCLUDE_PATH . "tmp/test.config.ini.php";
+$testEnvironment->save();
+
+Environment::setGlobalEnvironmentManipulator(new TestingEnvironmentManipulator($testEnvironment));
+
+include PIWIK_INCLUDE_PATH . '/index.php';
\ No newline at end of file