Public Python functions are nowadays marked PyAPI_FUNC, not DL_IMPORT.
diff --git a/Doc/tools/undoc_symbols.py b/Doc/tools/undoc_symbols.py
index 3528106..d603a36 100644
--- a/Doc/tools/undoc_symbols.py
+++ b/Doc/tools/undoc_symbols.py
@@ -77,7 +77,7 @@
 
     incfiles = os.path.join(incdir, INCLUDEPATTERN)
 
-    fp = os.popen("ctags -IDL_IMPORT --c-types=%s -f - %s"
+    fp = os.popen("ctags -IPyAPI_FUNC --c-types=%s -f - %s"
                   % (TAG_KINDS, incfiles))
     dict = findnames(fp, prefix)
     names = dict.keys()