diff --git a/lib/tests/medialib_test.php b/lib/tests/medialib_test.php
index 20e5d6d734e..7a0ca53ce7d 100644
--- a/lib/tests/medialib_test.php
+++ b/lib/tests/medialib_test.php
@@ -413,6 +413,16 @@ class core_medialib_testcase extends advanced_testcase {
         $this->assertEquals($webm, $result[1]->out(false));
         $this->assertEquals(400, $w);
         $this->assertEquals(280, $h);
+
+        // Support for rtmp.
+        $rtmp = 'rtmp://rtmpsite.net/somestream';
+        $result = $mediamanager->split_alternatives($rtmp, $w, $h);
+        $this->assertEquals($rtmp, $result[0]->out(false));
+
+        // Invalid URL is not supported.
+        $invalid = 'mailto:user@example.com';
+        $result = $mediamanager->split_alternatives($invalid, $w, $h);
+        $this->assertEmpty($result);
     }
 
     /**
diff --git a/media/classes/manager.php b/media/classes/manager.php
index cab7edb7586..71c268977ed 100644
--- a/media/classes/manager.php
+++ b/media/classes/manager.php
@@ -425,11 +425,17 @@ final class core_media_manager {
                 $url = str_replace($matches[0], '', $url);
             }
 
-            // Clean up url.
+            // Clean up url. Allow rtmp:// protocol even though it's not allowed by clean_param(..., PARAM_URL).
+            if ($isrtmp = preg_match('|^(rtmp://)(.*)$|i', trim($url), $matches)) {
+                $url = "http://" . $matches[2];
+            }
             $url = clean_param($url, PARAM_URL);
             if (empty($url)) {
                 continue;
             }
+            if ($isrtmp) {
+                $url = preg_replace('|^http://|', $matches[1], $url);
+            }
 
             // Turn it into moodle_url object.
             $returnurls[] = new moodle_url($url);