diff --git a/multipart/multipart.py b/multipart/multipart.py
index 47e00a7..a8fccee 100644
--- a/multipart/multipart.py
+++ b/multipart/multipart.py
@@ -1846,7 +1846,7 @@ def parse_form(
 
     while True:
         # Read only up to the Content-Length given.
-        max_readable = min(content_length - bytes_read, chunk_size)
+        max_readable = int(min(content_length - bytes_read, chunk_size))
         buff = input_stream.read(max_readable)
 
         # Write to the parser and update our length.