diff --git a/core/includes/errors.inc b/core/includes/errors.inc
index b96b828..3905800 100644
--- a/core/includes/errors.inc
+++ b/core/includes/errors.inc
@@ -87,9 +87,9 @@ function _drupal_error_handler_real($error_level, $message, $filename, $line, $c
 /**
  * Determines whether an error should be displayed.
  *
- * When in maintenance mode or when error_level is ERROR_REPORTING_DISPLAY_ALL,
- * all errors should be displayed. For ERROR_REPORTING_DISPLAY_SOME, $error
- * will be examined to determine if it should be displayed.
+ * During installation or when error_level is ERROR_REPORTING_DISPLAY_ALL, all
+ * errors should be displayed. For ERROR_REPORTING_DISPLAY_SOME, $error will be
+ * examined to determine if it should be displayed.
  *
  * @param $error
  *   Optional error to examine for ERROR_REPORTING_DISPLAY_SOME.
@@ -98,7 +98,7 @@ function _drupal_error_handler_real($error_level, $message, $filename, $line, $c
  *   TRUE if an error should be displayed.
  */
 function error_displayable($error = NULL) {
-  if (defined('MAINTENANCE_MODE')) {
+  if (defined('MAINTENANCE_MODE') && MAINTENANCE_MODE == 'install') {
     return TRUE;
   }
   $error_level = _drupal_get_error_level();