diff --git a/ptulsconv/docparser/tag_compiler.py b/ptulsconv/docparser/tag_compiler.py
index 1bc4a71..5f30fc2 100644
--- a/ptulsconv/docparser/tag_compiler.py
+++ b/ptulsconv/docparser/tag_compiler.py
@@ -1,4 +1,3 @@
-import sys
 from collections import namedtuple
 from fractions import Fraction
 from typing import Iterator, Tuple, Callable, Generator, Dict, List
@@ -72,9 +71,9 @@ class TagCompiler:
     def _marker_tags(self, at):
         retval = dict()
         applicable = [(m, t) for (m, t) in self.session.markers_timed() if t <= at]
-        for marker, time in sorted(applicable, key=lambda x: x[1]):
-            retval.update(parse_tags(marker.comments).tag_dict)
-            retval.update(parse_tags(marker.name).tag_dict)
+        for marker, _ in sorted(applicable, key=lambda x: x[1]):
+            retval.update(parse_tags(marker.comments or "").tag_dict)
+            retval.update(parse_tags(marker.name or "").tag_dict)
 
         return retval
 
@@ -186,4 +185,4 @@ def apply_appends(source: Iterator,
             yield this_element
             this_element = element
 
-    yield this_element
\ No newline at end of file
+    yield this_element
diff --git a/ptulsconv/docparser/tagged_string_parser_visitor.py b/ptulsconv/docparser/tagged_string_parser_visitor.py
index 93bca0a..5aa8aed 100644
--- a/ptulsconv/docparser/tagged_string_parser_visitor.py
+++ b/ptulsconv/docparser/tagged_string_parser_visitor.py
@@ -28,14 +28,14 @@ tag_grammar = Grammar(
 )
 
 
-def parse_tags(prompt) -> "TaggedStringResult":
+def parse_tags(prompt: str) -> "TaggedStringResult":
     ast = tag_grammar.parse(prompt)
     return TagListVisitor().visit(ast)
 
 
 class TaggedStringResult:
-    content: Optional[str]
-    tag_dict: Optional[Dict[str, str]]
+    content: str
+    tag_dict: Dict[str, str]
     mode: TagPreModes
 
     def __init__(self, content, tag_dict, mode):