diff --git a/pwnshop/templates/base/selenium.py b/pwnshop/templates/base/selenium.py
index 04b9af8..3c293f6 100755
--- a/pwnshop/templates/base/selenium.py
+++ b/pwnshop/templates/base/selenium.py
@@ -66,6 +66,11 @@
 
 {% if challenge.print_page %}
 print("Retrieved the following HTML:")
+{% if challenge.ensure_html %}
+if "<html" not in browser.page_source.lower():
+    print("Doesn't look like we retrieved an HTML page...")
+    sys.exit(1)
+{% endif %}
 print(browser.page_source)
 {% endif %}