diff --git a/question/type/ddimageortext/lang/en/qtype_ddimagetoimage.php b/question/type/ddimageortext/lang/en/qtype_ddimagetoimage.php
index 1f744a6e232..e065751d67b 100644
--- a/question/type/ddimageortext/lang/en/qtype_ddimagetoimage.php
+++ b/question/type/ddimageortext/lang/en/qtype_ddimagetoimage.php
@@ -48,6 +48,7 @@ $string['formerror_nobgimage'] = 'You need to select an image to use as the back
 $string['infinite'] = 'Infinite';
 $string['label'] = 'Label';
 $string['nolabel'] = 'No label text';
+$string['pleasedraganimagetoeachdropregion'] = 'Your answer is not complete, please drag an image to each drop region.';
 $string['previewarea'] = 'Preview area -';
 $string['previewareaheader'] = 'Preview';
 $string['previewareamessage'] = '<ul><li>Select a background image file.</li><li>Select draggable images.</li><li>And define drop zones by selecting an image that the student must drag to the drop zone and drag it to where the student should drag it too.</li></ul>';
diff --git a/question/type/ddimageortext/question.php b/question/type/ddimageortext/question.php
index 9e76dcf5068..42439880685 100755
--- a/question/type/ddimageortext/question.php
+++ b/question/type/ddimageortext/question.php
@@ -99,6 +99,12 @@ class qtype_ddimagetoimage_question extends qtype_gapselect_question_base {
                                                                 $filearea, $args, $forcedownload);
         }
     }
+    public function get_validation_error(array $response) {
+        if ($this->is_complete_response($response)) {
+            return '';
+        }
+        return get_string('pleasedraganimagetoeachdropregion', 'qtype_ddimagetoimage');
+    }
 }
 
 
diff --git a/question/type/ddimageortext/renderer.php b/question/type/ddimageortext/renderer.php
index 4b28e5e8731..8805b2d9ea5 100755
--- a/question/type/ddimageortext/renderer.php
+++ b/question/type/ddimageortext/renderer.php
@@ -119,6 +119,11 @@ class qtype_ddimagetoimage_renderer extends qtype_with_combined_feedback_rendere
                                         $sendtojs,
                                         true,
                                         $jsmodule);
+        if ($qa->get_state() == question_state::$invalid) {
+            $output .= html_writer::nonempty_tag('div',
+                                        $question->get_validation_error($qa->get_last_qt_data()),
+                                        array('class' => 'validationerror'));
+        }
         return $output;
     }