diff --git a/search/classes/manager.php b/search/classes/manager.php
index fc5a7188e10..8a44bbf8dc0 100644
--- a/search/classes/manager.php
+++ b/search/classes/manager.php
@@ -1138,7 +1138,12 @@ class manager {
             }
 
             // Show a message before each request, indicating what will be indexed.
-            $context = \context::instance_by_id($request->contextid);
+            $context = \context::instance_by_id($request->contextid, IGNORE_MISSING);
+            if (!$context) {
+                $DB->delete_records('search_index_requests', ['id' => $request->id]);
+                $progress->output('Skipped deleted context: ' . $request->contextid);
+                continue;
+            }
             $contextname = $context->get_context_name();
             if ($request->searcharea) {
                 $contextname .= ' (search area: ' . $request->searcharea . ')';
diff --git a/search/tests/manager_test.php b/search/tests/manager_test.php
index 95fa82c1f47..617ead6ac6b 100644
--- a/search/tests/manager_test.php
+++ b/search/tests/manager_test.php
@@ -902,5 +902,24 @@ class search_manager_testcase extends advanced_testcase {
 
         // Confirm table is now empty.
         $this->assertEquals(0, $DB->count_records('search_index_requests'));
+
+        // Make a request for a course context...
+        $course = $generator->create_course();
+        $context = context_course::instance($course->id);
+        $search::request_index($context);
+
+        // ...but then delete it (note: delete_course spews output, so we throw it away).
+        ob_start();
+        delete_course($course);
+        ob_end_clean();
+
+        // Process requests - it should only note the deleted context.
+        $search->process_index_requests(10, $progress);
+        $out = $progress->get_buffer();
+        $progress->reset_buffer();
+        $this->assertContains('Skipped deleted context: ' . $context->id, $out);
+
+        // Confirm request table is now empty.
+        $this->assertEquals(0, $DB->count_records('search_index_requests'));
     }
 }