diff --git a/src/Core/CoreKernel.php b/src/Core/CoreKernel.php
index 5b234bbae..140d248af 100644
--- a/src/Core/CoreKernel.php
+++ b/src/Core/CoreKernel.php
@@ -318,7 +318,6 @@ class CoreKernel implements Kernel
      */
     protected function getDatabaseConfig()
     {
-
         /** @skipUpgrade */
         $databaseConfig = [
             "type" => getenv('SS_DATABASE_CLASS') ?: 'MySQLDatabase',
@@ -361,7 +360,7 @@ class CoreKernel implements Kernel
      */
     protected function getDatabasePrefix()
     {
-        return getenv('SS_DATABASE_PREFIX');
+        return getenv('SS_DATABASE_PREFIX') ?: '';
     }
 
     /**
@@ -406,8 +405,12 @@ class CoreKernel implements Kernel
             $database = str_replace('.', '', basename($databaseDir));
             $prefix = $this->getDatabasePrefix();
 
-            if ($prefix === false) {
+            if ($prefix) {
                 $prefix = 'SS_';
+            } else {
+                // If no prefix, hard-code prefix into database global
+                $prefix = '';
+                $database = 'SS_' . $database;
             }
 
             return $prefix . $database;
diff --git a/src/Dev/Install/Installer.php b/src/Dev/Install/Installer.php
index f0fe2ca82..3ee2154bb 100644
--- a/src/Dev/Install/Installer.php
+++ b/src/Dev/Install/Installer.php
@@ -212,7 +212,7 @@ PHP
         // Build db within HTTPApplication
         $app->execute($request, function (HTTPRequest $request) use ($config) {
             // Start session and execute
-            $request->getSession()->init();
+            $request->getSession()->init($request);
 
             // Output status
             $this->statusMessage("Building database schema...");
@@ -242,7 +242,7 @@ PHP
 
             $request->getSession()->set('username', $config['admin']['username']);
             $request->getSession()->set('password', $config['admin']['password']);
-            $request->getSession()->save();
+            $request->getSession()->save($request);
         }, true);
 
         // Check result of install