diff --git a/stapler/handlers.py b/stapler/handlers.py
index 667975d..5ef5046 100644
--- a/stapler/handlers.py
+++ b/stapler/handlers.py
@@ -252,7 +252,10 @@ class BaseHandler(abc.ABC, http.server.BaseHTTPRequestHandler):
         return self.__in_size
 
     def _get_length(self) -> int:
-        return max(0, int(self._get_header("Content-Length", "0")))
+        try:
+            return max(0, int(self._get_header("Content-Length", "0")))
+        except ValueError:
+            return 0
 
     def _get_header(self, key: str, default_value: str = "") -> str:
         if self._has_header(key):