diff --git a/packages/markitdown/src/markitdown/__main__.py b/packages/markitdown/src/markitdown/__main__.py
index 8266f5c..6a5d01b 100644
--- a/packages/markitdown/src/markitdown/__main__.py
+++ b/packages/markitdown/src/markitdown/__main__.py
@@ -139,7 +139,7 @@ def main():
         else:
             charset_hint = None
 
-    stream_info: str | None = None
+    stream_info = None
     if (
         extension_hint is not None
         or mime_type_hint is not None
diff --git a/packages/markitdown/src/markitdown/converters/_bing_serp_converter.py b/packages/markitdown/src/markitdown/converters/_bing_serp_converter.py
index 7dd9e24..3527d28 100644
--- a/packages/markitdown/src/markitdown/converters/_bing_serp_converter.py
+++ b/packages/markitdown/src/markitdown/converters/_bing_serp_converter.py
@@ -1,6 +1,7 @@
 import io
 import re
 import base64
+import binascii
 from urllib.parse import parse_qs, urlparse
 from typing import Any, BinaryIO, Optional
 from bs4 import BeautifulSoup
@@ -60,6 +61,8 @@ class BingSerpConverter(DocumentConverter):
         stream_info: StreamInfo,
         **kwargs: Any,  # Options to pass to the converter
     ) -> DocumentConverterResult:
+        assert stream_info.url is not None
+
         # Parse the query parameters
         parsed_params = parse_qs(urlparse(stream_info.url).query)
         query = parsed_params.get("q", [""])[0]
@@ -79,6 +82,9 @@ class BingSerpConverter(DocumentConverter):
         _markdownify = _CustomMarkdownify()
         results = list()
         for result in soup.find_all(class_="b_algo"):
+            if not hasattr(result, "find_all"):
+                continue
+
             # Rewrite redirect urls
             for a in result.find_all("a", href=True):
                 parsed_href = urlparse(a["href"])
diff --git a/packages/markitdown/src/markitdown/converters/_outlook_msg_converter.py b/packages/markitdown/src/markitdown/converters/_outlook_msg_converter.py
index 8e20dc5..d216bea 100644
--- a/packages/markitdown/src/markitdown/converters/_outlook_msg_converter.py
+++ b/packages/markitdown/src/markitdown/converters/_outlook_msg_converter.py
@@ -9,7 +9,7 @@ from .._exceptions import MissingDependencyException, MISSING_DEPENDENCY_MESSAGE
 _dependency_exc_info = None
 olefile = None
 try:
-    import olefile
+    import olefile  # type: ignore[no-redef]
 except ImportError:
     # Preserve the error and stack trace for later
     _dependency_exc_info = sys.exc_info()
@@ -56,12 +56,13 @@ class OutlookMsgConverter(DocumentConverter):
 
         # Brue force, check if it's an Outlook file
         try:
-            msg = olefile.OleFileIO(file_stream)
-            toc = "\n".join([str(stream) for stream in msg.listdir()])
-            return (
-                "__properties_version1.0" in toc
-                and "__recip_version1.0_#00000000" in toc
-            )
+            if olefile is not None:
+                msg = olefile.OleFileIO(file_stream)
+                toc = "\n".join([str(stream) for stream in msg.listdir()])
+                return (
+                    "__properties_version1.0" in toc
+                    and "__recip_version1.0_#00000000" in toc
+                )
         except Exception as e:
             pass
         finally:
@@ -89,7 +90,11 @@ class OutlookMsgConverter(DocumentConverter):
                 _dependency_exc_info[2]
             )
 
+        assert (
+            olefile is not None
+        )  # If we made it this far, olefile should be available
         msg = olefile.OleFileIO(file_stream)
+
         # Extract email metadata
         md_content = "# Email Message\n\n"
 
@@ -121,6 +126,7 @@ class OutlookMsgConverter(DocumentConverter):
 
     def _get_stream_data(self, msg: Any, stream_path: str) -> Union[str, None]:
         """Helper to safely extract and decode stream data from the MSG file."""
+        assert olefile is not None
         assert isinstance(
             msg, olefile.OleFileIO
         )  # Ensure msg is of the correct type (type hinting is not possible with the optional olefile package)
diff --git a/packages/markitdown/src/markitdown/converters/_rss_converter.py b/packages/markitdown/src/markitdown/converters/_rss_converter.py
index 31e5ad5..7c80d01 100644
--- a/packages/markitdown/src/markitdown/converters/_rss_converter.py
+++ b/packages/markitdown/src/markitdown/converters/_rss_converter.py
@@ -66,7 +66,7 @@ class RssConverter(DocumentConverter):
             file_stream.seek(cur_pos)
         return False
 
-    def _feed_type(self, doc: Any) -> str:
+    def _feed_type(self, doc: Any) -> str | None:
         if doc.getElementsByTagName("rss"):
             return "rss"
         elif doc.getElementsByTagName("feed"):
@@ -130,10 +130,10 @@ class RssConverter(DocumentConverter):
         Returns None if the feed type is not recognized or something goes wrong.
         """
         root = doc.getElementsByTagName("rss")[0]
-        channel = root.getElementsByTagName("channel")
-        if not channel:
-            return None
-        channel = channel[0]
+        channel_list = root.getElementsByTagName("channel")
+        if not channel_list:
+            raise ValueError("No channel found in RSS feed")
+        channel = channel_list[0]
         channel_title = self._get_data_by_tag_name(channel, "title")
         channel_description = self._get_data_by_tag_name(channel, "description")
         items = channel.getElementsByTagName("item")
@@ -141,8 +141,6 @@ class RssConverter(DocumentConverter):
             md_text = f"# {channel_title}\n"
         if channel_description:
             md_text += f"{channel_description}\n"
-        if not items:
-            items = []
         for item in items:
             title = self._get_data_by_tag_name(item, "title")
             description = self._get_data_by_tag_name(item, "description")
@@ -183,5 +181,6 @@ class RssConverter(DocumentConverter):
             return None
         fc = nodes[0].firstChild
         if fc:
-            return fc.data
+            if hasattr(fc, "data"):
+                return fc.data
         return None
diff --git a/packages/markitdown/src/markitdown/converters/_wikipedia_converter.py b/packages/markitdown/src/markitdown/converters/_wikipedia_converter.py
index 5b054af..39466c0 100644
--- a/packages/markitdown/src/markitdown/converters/_wikipedia_converter.py
+++ b/packages/markitdown/src/markitdown/converters/_wikipedia_converter.py
@@ -1,7 +1,7 @@
 import io
 import re
+import bs4
 from typing import Any, BinaryIO, Optional
-from bs4 import BeautifulSoup
 
 from .._base_converter import DocumentConverter, DocumentConverterResult
 from .._stream_info import StreamInfo
@@ -57,7 +57,7 @@ class WikipediaConverter(DocumentConverter):
     ) -> DocumentConverterResult:
         # Parse the stream
         encoding = "utf-8" if stream_info.charset is None else stream_info.charset
-        soup = BeautifulSoup(file_stream, "html.parser", from_encoding=encoding)
+        soup = bs4.BeautifulSoup(file_stream, "html.parser", from_encoding=encoding)
 
         # Remove javascript and style blocks
         for script in soup(["script", "style"]):
@@ -72,9 +72,8 @@ class WikipediaConverter(DocumentConverter):
 
         if body_elm:
             # What's the title
-            if title_elm and len(title_elm) > 0:
-                main_title = title_elm.string  # type: ignore
-                assert isinstance(main_title, str)
+            if title_elm and isinstance(title_elm, bs4.Tag):
+                main_title = title_elm.string
 
             # Convert the page
             webpage_text = f"# {main_title}\n\n" + _CustomMarkdownify().convert_soup(
diff --git a/packages/markitdown/src/markitdown/converters/_youtube_converter.py b/packages/markitdown/src/markitdown/converters/_youtube_converter.py
index 5a158d5..2ee5c69 100644
--- a/packages/markitdown/src/markitdown/converters/_youtube_converter.py
+++ b/packages/markitdown/src/markitdown/converters/_youtube_converter.py
@@ -3,9 +3,9 @@ import json
 import time
 import io
 import re
+import bs4
 from typing import Any, BinaryIO, Optional, Dict, List, Union
 from urllib.parse import parse_qs, urlparse, unquote
-from bs4 import BeautifulSoup
 
 from .._base_converter import DocumentConverter, DocumentConverterResult
 from .._stream_info import StreamInfo
@@ -72,21 +72,31 @@ class YouTubeConverter(DocumentConverter):
     ) -> DocumentConverterResult:
         # Parse the stream
         encoding = "utf-8" if stream_info.charset is None else stream_info.charset
-        soup = BeautifulSoup(file_stream, "html.parser", from_encoding=encoding)
+        soup = bs4.BeautifulSoup(file_stream, "html.parser", from_encoding=encoding)
 
         # Read the meta tags
-        metadata: Dict[str, str] = {"title": soup.title.string}
+        metadata: Dict[str, str] = {}
+
+        if soup.title and soup.title.string:
+            metadata["title"] = soup.title.string
+
         for meta in soup(["meta"]):
+            if not isinstance(meta, bs4.Tag):
+                continue
+
             for a in meta.attrs:
                 if a in ["itemprop", "property", "name"]:
-                    content = meta.get("content", "")
-                    if content:  # Only add non-empty content
-                        metadata[meta[a]] = content
+                    key = str(meta.get(a, ""))
+                    content = str(meta.get("content", ""))
+                    if key and content:  # Only add non-empty content
+                        metadata[key] = content
                     break
 
         # Try reading the description
         try:
             for script in soup(["script"]):
+                if not isinstance(script, bs4.Tag):
+                    continue
                 if not script.string:  # Skip empty scripts
                     continue
                 content = script.string
@@ -161,7 +171,7 @@ class YouTubeConverter(DocumentConverter):
             if transcript_text:
                 webpage_text += f"\n### Transcript\n{transcript_text}\n"
 
-        title = title if title else soup.title.string
+        title = title if title else (soup.title.string if soup.title else "")
         assert isinstance(title, str)
 
         return DocumentConverterResult(
diff --git a/packages/markitdown/tests/test_cli_vectors.py b/packages/markitdown/tests/test_cli_vectors.py
index b2f068c..64128d6 100644
--- a/packages/markitdown/tests/test_cli_vectors.py
+++ b/packages/markitdown/tests/test_cli_vectors.py
@@ -114,7 +114,9 @@ def test_input_from_stdin_without_hints(shared_tmp_dir, test_vector) -> None:
     )
 
     stdout = result.stdout.decode(locale.getpreferredencoding())
-    assert result.returncode == 0, f"CLI exited with error: {result.stderr}"
+    assert (
+        result.returncode == 0
+    ), f"CLI exited with error: {result.stderr.decode('utf-8')}"
     for test_string in test_vector.must_include:
         assert test_string in stdout
     for test_string in test_vector.must_not_include: