diff --git a/CHANGES.txt b/CHANGES.txt
index e5ce95b73fe..25853755a09 100644
--- a/CHANGES.txt
+++ b/CHANGES.txt
@@ -38,3 +38,5 @@ CHANGES
 - Enable passing pre-compressed data in requests #621
 
 - Expose named routes via UrlDispatcher.named_routes() #622
+
+- Allow disabling sendfile by environment variable AIOHTTP_NOSENDFILE #629
diff --git a/aiohttp/web_urldispatcher.py b/aiohttp/web_urldispatcher.py
index 17ce659eb22..6627b82cd4f 100644
--- a/aiohttp/web_urldispatcher.py
+++ b/aiohttp/web_urldispatcher.py
@@ -163,7 +163,7 @@ def __init__(self, name, prefix, directory, *,
             raise ValueError(
                 "No directory exists at '{}'".format(self._directory))
 
-        if os.environ.get("AIOHTTP_NOSENDFILE") == "1":
+        if bool(os.environ.get("AIOHTTP_NOSENDFILE")):
             self._sendfile = self._sendfile_fallback
 
     def match(self, path):