diff --git a/lib/filterlib.php b/lib/filterlib.php
index 5f848ec604f..0f6072c1dfd 100644
--- a/lib/filterlib.php
+++ b/lib/filterlib.php
@@ -81,7 +81,7 @@ class filter_manager {
     public static function instance() {
         global $CFG;
         if (is_null(self::$singletoninstance)) {
-            if (!empty($CFG->perfdebug)) {
+            if (!empty($CFG->perfdebug) and $CFG->perfdebug > 7) {
                 self::$singletoninstance = new performance_measuring_filter_manager();
             } else {
                 self::$singletoninstance = new self();
diff --git a/lib/tests/filterlib_test.php b/lib/tests/filterlib_test.php
index 2db0568e2e0..e769e087eaf 100644
--- a/lib/tests/filterlib_test.php
+++ b/lib/tests/filterlib_test.php
@@ -660,4 +660,19 @@ class core_filterlib_testcase extends advanced_testcase {
         $this->assertEquals('emailprotect,multilang', $CFG->stringfilters);
         $this->assertEquals(1, $CFG->filterall);
     }
+
+    public function test_filter_manager_instance() {
+
+        set_config('perfdebug', 7);
+        filter_manager::reset_caches();
+        $filterman = filter_manager::instance();
+        $this->assertInstanceOf('filter_manager', $filterman);
+        $this->assertNotInstanceOf('performance_measuring_filter_manager', $filterman);
+
+        set_config('perfdebug', 15);
+        filter_manager::reset_caches();
+        $filterman = filter_manager::instance();
+        $this->assertInstanceOf('filter_manager', $filterman);
+        $this->assertInstanceOf('performance_measuring_filter_manager', $filterman);
+    }
 }