diff --git a/.htaccess b/.htaccess
index 7ccb6a2..2b46083 100644
--- a/.htaccess
+++ b/.htaccess
@@ -32,6 +32,9 @@ DirectoryIndex index.php index.html index.htm
   php_value mbstring.http_input             pass
   php_value mbstring.http_output            pass
   php_flag mbstring.encoding_translation    off
+  # PHP 5.6 has deprecated $HTTP_RAW_POST_DATA and produces warnings if this is
+  # not set.
+  php_value always_populate_raw_post_data   -1
 </IfModule>
 
 # Requires mod_expires to be enabled.
diff --git a/modules/file/file.install b/modules/file/file.install
index 47ee4fd..507416d 100644
--- a/modules/file/file.install
+++ b/modules/file/file.install
@@ -92,6 +92,14 @@ function file_requirements($phase) {
       'severity' => $severity,
       'description' => $description,
     );
+    if (version_compare(PHP_VERSION, '5.6.0') >= 0 && ini_get('always_populate_raw_post_data') != -1) {
+      $requirements['always_populate_raw_post_data'] = array(
+        'title' => t('always_populate_raw_post_data PHP setting'),
+        'value' => t('Not set to -1.'),
+        'severity' => REQUIREMENT_ERROR,
+        'description' => t('The always_populate_raw_post_data PHP setting should be set to -1 in PHP versions 5.6 and up. Please check the <a href="https://php.net/manual/en/ini.core.php#ini.always-populate-raw-post-data">HP manual</a> for information on how to correct this.'),
+      );
+    }
   }
 
   return $requirements;