diff --git a/.gitignore b/.gitignore
index 22e6381..0643b27 100644
--- a/.gitignore
+++ b/.gitignore
@@ -66,4 +66,8 @@ cache/
 .idea/
 
 # Old folder from v2?
-media/
\ No newline at end of file
+media/
+
+# Python venv
+.venv/
+venv/
diff --git a/iiify/resolver.py b/iiify/resolver.py
index 49288e5..5ef653b 100644
--- a/iiify/resolver.py
+++ b/iiify/resolver.py
@@ -36,7 +36,7 @@ class IsCollection(Exception):
     pass
 
 def purify_domain(domain):
-    domain = re.sub('^http:\/\/', "https://", domain)
+    domain = re.sub(r'^http:\/\/', "https://", domain)
     return domain if domain.endswith('/iiif/') else domain + 'iiif/'
 
 
@@ -704,7 +704,7 @@ def create_manifest3(identifier, domain=None, page=None):
 
             if f['format'] == 'Web Video Text Tracks':
                 # Example: cruz-test.en.vtt and 34C3_-_International_Image_Interoperability_Framework_IIIF_Kulturinstitutionen_schaffen_interop-SvH4fbjOT0A.autogenerated.vtt
-                sourceFilename = re.sub('\.[a-zA-H-]*\.vtt', '', f['name'])
+                sourceFilename = re.sub(r'\.[a-zA-H-]*\.vtt', '', f['name'])
                 if sourceFilename not in vttfiles:
                     vttfiles[sourceFilename] = []