diff --git a/sdks/python/apache_beam/io/filesystem.py b/sdks/python/apache_beam/io/filesystem.py
index bdc25dcf0fe5..6a0c67fd4a82 100644
--- a/sdks/python/apache_beam/io/filesystem.py
+++ b/sdks/python/apache_beam/io/filesystem.py
@@ -295,6 +295,9 @@ def read(self, num_bytes: Optional[int] = None) -> bytes:
     if not self._decompressor:
       raise ValueError('decompressor not initialized')
 
+    if num_bytes is None:
+      num_bytes = DEFAULT_READ_BUFFER_SIZE
+
     self._fetch_to_internal_buffer(num_bytes)
     return self._read_from_internal_buffer(
         lambda: self._read_buffer.read(num_bytes))
diff --git a/sdks/python/apache_beam/io/filesystem_test.py b/sdks/python/apache_beam/io/filesystem_test.py
index a4d456a366da..ff53648d692a 100644
--- a/sdks/python/apache_beam/io/filesystem_test.py
+++ b/sdks/python/apache_beam/io/filesystem_test.py
@@ -470,6 +470,21 @@ def test_read_and_seek_back_to_beginning(self):
 
         self.assertEqual(first_pass, second_pass)
 
+  def test_read(self):
+    for compression_type in [CompressionTypes.BZIP2,
+                             CompressionTypes.DEFLATE,
+                             CompressionTypes.GZIP,
+                             CompressionTypes.ZSTD,
+                             CompressionTypes.LZMA]:
+      file_name = self._create_compressed_file(compression_type, self.content)
+      with open(file_name, 'rb') as f:
+        compressed_fd = CompressedFile(
+            f, compression_type, read_size=self.read_block_size)
+
+        data = compressed_fd.read()
+
+        self.assertEqual(data, self.content)
+
   def test_tell(self):
     lines = [b'line%d\n' % i for i in range(10)]
     tmpfile = self._create_temp_file()