diff --git a/config-dist.php b/config-dist.php
index 1f760c3608b..6ba8657c367 100644
--- a/config-dist.php
+++ b/config-dist.php
@@ -409,6 +409,9 @@ $CFG->admin = 'admin';
 //   Print to footer (works with the default theme)
 //   define('MDL_PERFTOFOOT', true);
 //
+//   Print additional data to log of included files
+//   define('MDL_PERFINC', true);
+//
 //   Enable earlier profiling that causes more code to be covered
 //   on every request (db connections, config load, other inits...).
 //   Requires extra configuration to be defined in config.php like:
diff --git a/lib/classes/shutdown_manager.php b/lib/classes/shutdown_manager.php
index 437d8a4451c..955b0ed5dc4 100644
--- a/lib/classes/shutdown_manager.php
+++ b/lib/classes/shutdown_manager.php
@@ -204,15 +204,15 @@ class core_shutdown_manager {
         }
 
         // Deal with perf logging.
-        if (defined('MDL_PERF') || (!empty($CFG->perfdebug) and $CFG->perfdebug > 7)) {
+        if ((defined('MDL_PERF') && MDL_PERF) || (!empty($CFG->perfdebug) && $CFG->perfdebug > 7)) {
             if ($apachereleasemem) {
                 error_log('Mem usage over '.$apachereleasemem.': marking Apache child for reaping.');
             }
-            if (defined('MDL_PERFTOLOG')) {
+            if (defined('MDL_PERFTOLOG') && MDL_PERFTOLOG) {
                 $perf = get_performance_info();
                 error_log("PERF: " . $perf['txt']);
             }
-            if (defined('MDL_PERFINC')) {
+            if (defined('MDL_PERFINC') && MDL_PERFINC) {
                 $inc = get_included_files();
                 $ts  = 0;
                 foreach ($inc as $f) {
diff --git a/lib/outputrenderers.php b/lib/outputrenderers.php
index cd392da2aa8..db385f8660e 100644
--- a/lib/outputrenderers.php
+++ b/lib/outputrenderers.php
@@ -1435,9 +1435,9 @@ class core_renderer extends renderer_base {
 
         // Provide some performance info if required
         $performanceinfo = '';
-        if (defined('MDL_PERF') || (!empty($CFG->perfdebug) and $CFG->perfdebug > 7)) {
+        if ((defined('MDL_PERF') && MDL_PERF) || (!empty($CFG->perfdebug) && $CFG->perfdebug > 7)) {
             $perf = get_performance_info();
-            if (defined('MDL_PERFTOFOOT') || debugging() || $CFG->perfdebug > 7) {
+            if ((defined('MDL_PERFTOFOOT') && MDL_PERFTOFOOT) || debugging() || $CFG->perfdebug > 7) {
                 $performanceinfo = $perf['html'];
             }
         }