diff --git a/openflexure_microscope/api/utilities/gui.py b/openflexure_microscope/api/utilities/gui.py
index 19d83bd8..1a6a11ef 100644
--- a/openflexure_microscope/api/utilities/gui.py
+++ b/openflexure_microscope/api/utilities/gui.py
@@ -7,10 +7,18 @@ def build_gui_from_dict(gui_description, extension_object):
     # Make a working copy of GUI description
     api_gui = copy.deepcopy(gui_description)
 
+    logging.debug(extension_object._rules)
+
     # Expand shorthand routes into full relative URLs
     if "forms" in gui_description and isinstance(api_gui["forms"], list):
         for form in api_gui["forms"]:
+            # Clean leading slashes from rule
+            if "route" in form:
+                while form["route"][0] == "/":
+                    form["route"] = form["route"][1:]
+            # Match rule in extension object
             if "route" in form and form["route"] in extension_object._rules.keys():
+                logging.debug(f"Expanding {form}")
                 form["route"] = extension_object._rules[form["route"]]["rule"]
             else:
                 logging.warn(