diff --git a/fb_social.install b/fb_social.install
index f833da8..e6766e0 100644
--- a/fb_social.install
+++ b/fb_social.install
@@ -5,6 +5,37 @@
  */
 
 /**
+ * Implements hook_requirements().
+ */
+function fb_social_requirements($phase) {
+  $requirements = array();
+  $t = get_t();
+
+  // The PHP module for OpenSSL is required.
+  if (extension_loaded('openssl')) {
+    $severity = REQUIREMENT_OK;
+    $message = $t('OpenSSL extension enabled.');
+    $description = '';
+  }
+  // If the PHP module is not available do not prevent the site from being
+  // installed or working, but at least warn the site builder.
+  else {
+    $severity = REQUIREMENT_WARNING;
+    $message = $t('OpenSSL extension not enabled.');
+    $description = $t("Facebook Social presets require the PHP OpenSSL extension to be loaded.");
+  }
+
+  $requirements['fb_social_openssl'] = array(
+    'title' => $t('OpenSSL'),
+    'value' => $message,
+    'severity' => $severity,
+    'description' => $description,
+  );
+
+  return $requirements;
+}
+
+/**
  * Implements hook_install().
  */
 function fb_social_install() {