diff --git a/examples/split_silence.py b/examples/split_silence.py
index a889db1..90b46d9 100755
--- a/examples/split_silence.py
+++ b/examples/split_silence.py
@@ -27,10 +27,10 @@ parser.add_argument('--start-time', type=float, help='Start time (seconds)')
 parser.add_argument('--end-time', type=float, help='End time (seconds)')
 parser.add_argument('-v', dest='verbose', action='store_true', help='Verbose mode')
 
-silence_start_re = re.compile(' silence_start: (?P<start>[0-9]+(\.?[0-9]*))$')
-silence_end_re = re.compile(' silence_end: (?P<end>[0-9]+(\.?[0-9]*)) ')
+silence_start_re = re.compile(r' silence_start: (?P<start>[0-9]+(\.?[0-9]*))$')
+silence_end_re = re.compile(r' silence_end: (?P<end>[0-9]+(\.?[0-9]*)) ')
 total_duration_re = re.compile(
-    'size=[^ ]+ time=(?P<hours>[0-9]{2}):(?P<minutes>[0-9]{2}):(?P<seconds>[0-9\.]{5}) bitrate=')
+    r'size=[^ ]+ time=(?P<hours>[0-9]{2}):(?P<minutes>[0-9]{2}):(?P<seconds>[0-9\.]{5}) bitrate=')
 
 
 def _logged_popen(cmd_line, *args, **kwargs):
diff --git a/ffmpeg/tests/test_ffmpeg.py b/ffmpeg/tests/test_ffmpeg.py
index 51ee258..880b5c4 100644
--- a/ffmpeg/tests/test_ffmpeg.py
+++ b/ffmpeg/tests/test_ffmpeg.py
@@ -30,7 +30,7 @@ subprocess.check_call(['ffmpeg', '-version'])
 
 
 def test_escape_chars():
-    assert ffmpeg._utils.escape_chars('a:b', ':') == 'a\:b'
+    assert ffmpeg._utils.escape_chars('a:b', ':') == r'a\:b'
     assert ffmpeg._utils.escape_chars('a\\:b', ':\\') == 'a\\\\\\:b'
     assert (
         ffmpeg._utils.escape_chars('a:b,c[d]e%{}f\'g\'h\\i', '\\\':,[]%')