diff --git a/install.php b/install.php
index fe6dcbed..6c4fa8d0 100644
--- a/install.php
+++ b/install.php
@@ -435,8 +435,8 @@ function write_config() { // {{{
 		mkdir("data/config", 0755, true);
 	}
 	
-	if(!file_put_contents("data/config/shimmie.conf.php", $file_content)) {
-		$h_file_content = htmlentities($file_content);
+	if(!file_put_contents("data/config/shimmie.conf.php", $file_content, LOCK_EX)) {
+		$h_file_content = htmlentities($file_content);[
 		print <<<EOD
 		<div id="installer">
 			<h1>Shimmie Installer</h1>
diff --git a/tests/all_tests.php b/tests/all_tests.php
index 026604db..1f181d40 100644
--- a/tests/all_tests.php
+++ b/tests/all_tests.php
@@ -30,15 +30,23 @@ define("_TRAVIS_DATABASE", $db);
 $test_suite = new TestSuite('Shimmie tests');
 $test_suite->add(new ShimmieInstallerTest());
 
-// 
-// From index.php
-//
+// Wait for the config file to be written.
 
-clearstatcache();
+$timeout = 5;
+
+while ($timeout > 0 && !file_exists("data/config/shimmie.conf.php")) {
+	sleep(1);
+	$timout--;
+	clearstatcache();
+}
 
 require_once("core/sys_config.inc.php");
 include "data/config/shimmie.conf.php";
 
+// 
+// The code below is from index.php
+//
+
 // set up and purify the environment
 _version_check();
 _sanitise_environment();