diff --git a/moviepy/video/io/ffmpeg_reader.py b/moviepy/video/io/ffmpeg_reader.py
index 1b7fb5682..1086fe54e 100644
--- a/moviepy/video/io/ffmpeg_reader.py
+++ b/moviepy/video/io/ffmpeg_reader.py
@@ -385,7 +385,7 @@ def get_fps():
         line = lines_audio[0]
         try:
             match = re.search(" [0-9]* Hz", line)
-            hz_string = line[match.start()+1:match.end()-3]
+            hz_string = line[match.start()+1:match.end()-3]  # Removes the 'hz' from the end
             result['audio_fps'] = int(hz_string)
         except:
             result['audio_fps'] = 'unknown'