diff --git a/public/lib/filelib.php b/public/lib/filelib.php
index e46df988fce..840ed79b6aa 100644
--- a/public/lib/filelib.php
+++ b/public/lib/filelib.php
@@ -3639,6 +3639,10 @@ class curl {
                 $options[$n] = $v;
             }
             $handles[$i] = curl_init($requests[$i]['url']);
+
+            // Set the URL as a curl option.
+            $this->setopt(['CURLOPT_URL' => $requests[$i]['url']]);
+
             $this->apply_opt($handles[$i], $options);
             curl_multi_add_handle($main, $handles[$i]);
         }
diff --git a/public/lib/tests/filelib_test.php b/public/lib/tests/filelib_test.php
index f0414ad7473..ae7a87edb09 100644
--- a/public/lib/tests/filelib_test.php
+++ b/public/lib/tests/filelib_test.php
@@ -511,6 +511,27 @@ final class filelib_test extends \advanced_testcase {
         $this->assertNotEquals(0, $curl->get_errno());
         $this->assertNotEquals('47250a973d1b88d9445f94db4ef2c97a', md5($contents));
 
+        // Test multiple queries with proxy.
+        $curl = new \curl(['debug' => 1]);
+        ob_start();
+        $requests = [[
+            'nobody' => true,
+            'header' => 1,
+            'url' => $testurl,
+            'returntransfer' => true,
+        ],
+        [
+            'nobody' => true,
+            'header' => 1,
+            'url' => $testurl,
+            'returntransfer' => true,
+        ]];
+        $curl->download($requests);
+        $output = ob_get_contents();
+        ob_end_clean();
+        // We must have exactly 2 occurrences of ["CURLOPT_PROXY"].
+        $this->assertMatchesRegularExpression('/(\["CURLOPT_PROXY"\].*){2}/ms', $output);
+
         // Test with proxy bypass.
         $testurlhost = parse_url($testurl, PHP_URL_HOST);
         $CFG->proxybypass = $testurlhost;
@@ -519,6 +540,26 @@ final class filelib_test extends \advanced_testcase {
         $this->assertSame(0, $curl->get_errno());
         $this->assertSame('47250a973d1b88d9445f94db4ef2c97a', md5($contents));
 
+        // Test multiple queries with proxy bypass.
+        $curl = new \curl(['debug' => 1]);
+        ob_start();
+        $requests = [[
+            'nobody' => true,
+            'header' => 1,
+            'url' => $testurl,
+            'returntransfer' => true,
+        ],
+        [
+            'nobody' => true,
+            'header' => 1,
+            'url' => $testurl,
+            'returntransfer' => true,
+        ]];
+        $curl->download($requests);
+        $output = ob_get_contents();
+        ob_end_clean();
+        $this->assertStringNotContainsString('["CURLOPT_PROXY"]', $output);
+
         $CFG->proxyhost = $oldproxy;
         $CFG->proxybypass = $oldproxybypass;
     }