diff --git a/webvtt/models.py b/webvtt/models.py
index 1eade27..fe3e981 100644
--- a/webvtt/models.py
+++ b/webvtt/models.py
@@ -9,7 +9,7 @@
 class Timestamp:
     """Representation of a timestamp."""
 
-    PATTERN = re.compile(r'(?:(\d{1,2}):)?(\d{1,2}):(\d{1,2})\.(\d{3})')
+    PATTERN = re.compile(r'(?:(\d{1,}):)?(\d{1,2}):(\d{1,2})\.(\d{3})')
 
     def __init__(
             self,