diff --git a/exercises/CSS/Responsive/index.html b/exercises/CSS/Responsive/index.html
index 5802d7e..fe6a22b 100644
--- a/exercises/CSS/Responsive/index.html
+++ b/exercises/CSS/Responsive/index.html
@@ -13,7 +13,7 @@
     <a class="invisible" id="save-button">Save JSON</a>
     <button class="basic-button" id="file-opener-button">Open IFC</button>
 </div>
-<input class="invisible" id="file-input" type="file">
+<input class="invisible" id="file-input" type="file" accept=".ifc, .ifcXML, .ifcZIP">
 <div class="general-container">
     <div class="container" id="left-container"></div>
     <div class="separator"></div>
@@ -21,4 +21,4 @@
 </div>
 <script src="bundle.js"></script>
 </body>
-</html>
\ No newline at end of file
+</html>