diff --git a/composer.json b/composer.json
index b9ff27c..fa2256c 100644
--- a/composer.json
+++ b/composer.json
@@ -31,12 +31,12 @@
         "source": "https://github.com/picocms/Pico"
     },
     "require": {
-        "php": ">=5.3.6",
+        "php": "^7.0.8",
         "ext-mbstring": "*",
-        "twig/twig": "^1.36",
-        "symfony/yaml" : "^2.8",
-        "erusev/parsedown": "1.8.0-beta-7",
-        "erusev/parsedown-extra": "0.8.0-beta-1"
+        "twig/twig": "^2.12",
+        "symfony/yaml" : "^3.4",
+        "erusev/parsedown": "1.7.4",
+        "erusev/parsedown-extra": "0.8.1"
     },
     "suggest": {
         "picocms/pico-theme": "Pico requires a theme to actually display the contents of your website. This is Pico's official default theme.",
diff --git a/index.php.dist b/index.php.dist
index a1f981d..46c6ddb 100644
--- a/index.php.dist
+++ b/index.php.dist
@@ -11,8 +11,8 @@
  */
 
 // check PHP platform requirements
-if (PHP_VERSION_ID < 50306) {
-    die('Pico requires PHP 5.3.6 or above to run');
+if (PHP_VERSION_ID < 70008) {
+    die('Pico requires PHP 7.0.8 or above to run');
 }
 if (!extension_loaded('dom')) {
     die("Pico requires the PHP extension 'dom' to run");