diff --git a/sabnzbd/deobfuscate_filenames.py b/sabnzbd/deobfuscate_filenames.py
index 37e4c1f..68f9957 100644
--- a/sabnzbd/deobfuscate_filenames.py
+++ b/sabnzbd/deobfuscate_filenames.py
@@ -166,7 +166,7 @@ def deobfuscate_list(filelist: List[str], usefulname: str):
     # 2. if no meaningful extension, add it
     # 3. based on detecting obfuscated filenames
 
-    # to be sure, only keep really exsiting files:
+    # to be sure, only keep really existing files:
     filelist = [f for f in filelist if os.path.isfile(f)]
 
     # let's see if there are files with uncommon/unpopular (so: obfuscated) extensions
@@ -176,7 +176,7 @@ def deobfuscate_list(filelist: List[str], usefulname: str):
     for file in filelist:
         if file_extension.has_popular_extension(file):
             # common extension, like .doc or .iso, so assume OK and change nothing
-            logging.debug("extension of %s looks common", file)
+            logging.debug("Extension of %s looks common", file)
             newlist.append(file)
         else:
             # uncommon (so: obfuscated) extension
@@ -220,6 +220,7 @@ def deobfuscate_list(filelist: List[str], usefulname: str):
         # check that file is still there (and not renamed by the secondary renaming process below)
         if not os.path.isfile(filename):
             continue
+
         logging.debug("Deobfuscate inspecting %s", filename)
         # Do we need to rename this file?
         # Criteria: big, not-excluded extension, obfuscated (in that order)
diff --git a/sabnzbd/utils/file_extension.py b/sabnzbd/utils/file_extension.py
index 5432ac3..b12e879 100644
--- a/sabnzbd/utils/file_extension.py
+++ b/sabnzbd/utils/file_extension.py
@@ -8,10 +8,11 @@ Note: extension always contains a leading dot
 import puremagic
 import os
 import sys
+import re
 from typing import List
-from pathlib import Path
 from sabnzbd.filesystem import get_ext
 
+
 # common extension from https://www.computerhope.com/issues/ch001789.htm
 POPULAR_EXT = (
     "3g2",
@@ -234,16 +235,19 @@ DOWNLOAD_EXT = (
     "xpi",
 )
 
-# combine to one tuple, with unique entries:
+# Combine to one tuple, with unique entries:
 ALL_EXT = tuple(set(POPULAR_EXT + DOWNLOAD_EXT))
-# prepend a dot to each extension, because we work with a leading dot in extensions
+# Prepend a dot to each extension, because we work with a leading dot in extensions
 ALL_EXT = tuple(["." + i for i in ALL_EXT])
 
+# Match old-style multi-rar extensions
+SIMPLE_RAR_RE = re.compile(r"\.r\d\d\d?$", re.I)
+
 
 def has_popular_extension(file_path: str) -> bool:
     """returns boolean if the extension of file_path is a popular, well-known extension"""
     file_extension = get_ext(file_path)
-    return file_extension in ALL_EXT
+    return file_extension in ALL_EXT or SIMPLE_RAR_RE.match(file_extension)
 
 
 def all_possible_extensions(file_path: str) -> List[str]:
diff --git a/tests/test_file_extension.py b/tests/test_file_extension.py
index 0d1ed00..81370a7 100644
--- a/tests/test_file_extension.py
+++ b/tests/test_file_extension.py
@@ -29,6 +29,10 @@ class Test_File_Extension:
         assert file_extension.has_popular_extension("blabla/blabla.mkv")
         assert file_extension.has_popular_extension("blabla/blabla.srt")
         assert file_extension.has_popular_extension("djjddj/aaaaa.epub")
+        assert file_extension.has_popular_extension("test/testing.r01")
+        assert file_extension.has_popular_extension("test/testing.r901")
+        assert not file_extension.has_popular_extension("test/testing")
+        assert not file_extension.has_popular_extension("test/testing.rar01")
         assert not file_extension.has_popular_extension("98ads098f098fa.a0ds98f098asdf")
 
     def test_what_is_most_likely_extension(self):