diff --git a/scripts/wrap/parse.py b/scripts/wrap/parse.py
index 1954101af..7079c8170 100644
--- a/scripts/wrap/parse.py
+++ b/scripts/wrap/parse.py
@@ -2,6 +2,7 @@
 Support for accessing parse tree for MuPDF headers.
 '''
 
+import collections
 import os
 import sys
 import time
@@ -9,7 +10,7 @@ import time
 import jlib
 
 try:
-    import clang
+    import clang.cindex
 except ImportError as e:
     jlib.log( 'Warning, could not import clang: {e}')
     clang = None
@@ -487,6 +488,10 @@ class Arg:
 
 get_args_cache = dict()
 
+# get_args() needs to know how to get something hashable from a clang.cindex.Cursor.
+if clang:
+    g_cursor_is_hashable = issubclass(clang.cindex.Cursor, collections.abc.Hashable)
+
 def get_args( tu, cursor, include_fz_context=False, skip_first_alt=False, verbose=False):
     '''
     Yields Arg instance for each arg of the function at <cursor>.
@@ -509,7 +514,10 @@ def get_args( tu, cursor, include_fz_context=False, skip_first_alt=False, verbos
     #
     if verbose:
         jlib.log( '## Looking at args of {cursor.spelling=}')
-    key = tu, cursor.location.file, cursor.location.line, include_fz_context, skip_first_alt
+    if g_cursor_is_hashable:
+        key = tu, cursor, include_fz_context, skip_first_alt
+    else:
+        key = tu, cursor.location.file, cursor.location.line, include_fz_context, skip_first_alt
     ret = get_args_cache.get( key)
     if not verbose and state.state_.show_details(cursor.spelling):
         verbose = True