diff --git a/warden_server/warden_server.py b/warden_server/warden_server.py
index 25acd57f9be46c169ee5b68de1da3e428c2ac83b..c69fb6a7799d5de101d3ce8eb7fdb4071f24f19e 100755
--- a/warden_server/warden_server.py
+++ b/warden_server/warden_server.py
@@ -927,10 +927,10 @@ class Server(ObjectBase):
             # preserve compatibility with clients deployed in the wild, which use POST for
             # all requests (even those without payload, with no specified content length).
             # According to PEP3333, section "Input and Error Streams", the application SHOULD
-            # NOT attempt to read more data than specified by CONTENT-LENGTH. As stated in
-            # section "environ Variables", CONTENT-LENGTH may be empty (string) or absent.
+            # NOT attempt to read more data than specified by CONTENT_LENGTH. As stated in
+            # section "environ Variables", CONTENT_LENGTH may be empty (string) or absent.
             try:
-                content_length = int(environ.get('CONTENT-LENGTH', 0))
+                content_length = int(environ.get('CONTENT_LENGTH', 0))
             except ValueError:
                 content_length = 0