diff --git a/openoutreach.install b/openoutreach.install
index 2314609..e2f122b 100644
--- a/openoutreach.install
+++ b/openoutreach.install
@@ -4,6 +4,11 @@
  * @file
  * Install function for the openoutreach profile.
  */
+ 
+/**
+ * Minimum value of PHP memory_limit for SimpleTest.
+ */
+define('OPENOUTREACH_MINIMUM_PHP_MEMORY_LIMIT', '128M');
 
 /**
  * Implements hook_install().
@@ -143,6 +148,57 @@ function openoutreach_install() {
 }
 
 /**
+ * Implements hook_install().
+ */
+function simpletest_requirements($phase) {
+  $requirements = array();
+  $t = get_t();
+
+  // Check the current memory limit. If it is set too low and many Open
+  // Outreach apps are enabled, page loads at certain paths may fail and
+  // throw a fatal error.
+  $memory_limit = ini_get('memory_limit');
+  if (!openoutreach_check_memory_limit(OPENOUTREACH_MINIMUM_PHP_MEMORY_LIMIT, $memory_limit)) {
+    $requirements['php_memory_limit']['severity'] = REQUIREMENT_WARNING;
+    $requirements['php_memory_limit']['description'] = $t('The recommended PHP memory limit for running Open Outreach is at least %memory_minimum_limit. The current value is %memory_limit. <a href="@limit_url">Follow these steps to increase the PHP memory limit</a>. Alternately, if you are using a commercial host, you may wish to switch to a host that better supports Drupal and Open Outreach. See the <a href="@hosting_url">Open Outreach hosting listings</a> for some options.', array('%memory_limit' => $memory_limit, '%memory_minimum_limit' => OPENOUTREACH_MINIMUM_PHP_MEMORY_LIMIT, '@limit_url' => 'http://drupal.org/node/207036', '@hosting_url' => 'http://openoutreach.org/hosting'));
+  }
+
+  return $requirements;
+}
+
+/**
+ * Compares the memory required for an operation to the available memory.
+ *
+ * @todo: use drupal_check_memory_limit() when upgrading to Drupal 8.
+ *
+ * @param $required
+ *   The memory required for the operation, expressed as a number of bytes with
+ *   optional SI or IEC binary unit prefix (e.g. 2, 3K, 5MB, 10G, 6GiB, 8bytes,
+ *   9mbytes).
+ * @param $memory_limit
+ *   (optional) The memory limit for the operation, expressed as a number of
+ *   bytes with optional SI or IEC binary unit prefix (e.g. 2, 3K, 5MB, 10G,
+ *   6GiB, 8bytes, 9mbytes). If no value is passed, the current PHP
+ *   memory_limit will be used. Defaults to NULL.
+ *
+ * @return
+ *   TRUE if there is sufficient memory to allow the operation, or FALSE
+ *   otherwise.
+ */
+function openoutreach_check_memory_limit($required, $memory_limit = NULL) {
+  if (!isset($memory_limit)) {
+    $memory_limit = ini_get('memory_limit');
+  }
+
+  // There is sufficient memory if:
+  // - No memory limit is set.
+  // - The memory limit is set to unlimited (-1).
+  // - The memory limit is greater than or equal to the memory required for
+  //   the operation.
+  return ((!$memory_limit) || ($memory_limit == -1) || (parse_size($memory_limit) >= parse_size($required)));
+}
+
+/**
  * Enable openoutreach_core and apps modules.
  */
 function openoutreach_update_7000() {