diff --git a/lib/moodlelib.php b/lib/moodlelib.php
index e4062fe1cd6..1ebdebe3586 100644
--- a/lib/moodlelib.php
+++ b/lib/moodlelib.php
@@ -8273,7 +8273,8 @@ function get_device_type() {
          return 'tablet';
     }
 
-    if (strpos($_SERVER['HTTP_USER_AGENT'], 'MSIE 6.') !== false) {
+    // Safe way to check for IE6 and not get false positives for some IE 7/8 users
+    if (substr($_SERVER['HTTP_USER_AGENT'], 0, 34) === 'Mozilla/4.0 (compatible; MSIE 6.0;') {
         return 'legacy';
     }
 
diff --git a/lib/simpletest/testmoodlelib.php b/lib/simpletest/testmoodlelib.php
index f620ec54fdf..74f85cb71ce 100644
--- a/lib/simpletest/testmoodlelib.php
+++ b/lib/simpletest/testmoodlelib.php
@@ -296,6 +296,15 @@ class moodlelib_test extends UnitTestCase {
         $this->assertEqual(array('gecko', 'gecko19'), get_browser_version_classes());
     }
 
+    function test_get_device_type() {
+        // IE8 (common pattern ~1.5% of IE7/8 users have embedded IE6 agent))
+        $_SERVER['HTTP_USER_AGENT'] = 'Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 5.1; Trident/4.0; BT Openworld BB; Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1) ; Hotbar 10.2.197.0; .NET CLR 3.0.4506.2152; .NET CLR 3.5.30729; .NET CLR 2.0.50727)';
+        $this->assertEqual('default', get_device_type());
+        // Genuine IE6
+        $_SERVER['HTTP_USER_AGENT'] = 'Mozilla/4.0 (compatible; MSIE 6.0; AOL 9.0; Windows NT 5.1; SV1; FunWebProducts; .NET CLR 1.0.3705; Media Center PC 2.8)';
+        $this->assertEqual('legacy', get_device_type());
+    }
+
     function test_fix_utf8() {
         // make sure valid data including other types is not changed
         $this->assertidentical(null, fix_utf8(null));