1 files changed, 1 insertions, 1 deletions
diff --git a/SPEC b/SPEC
index 3352b843..59ec9d72 100644
--- a/SPEC
+++ b/SPEC
@@ -225,9 +225,9 @@ This is an HTTP status. When parsed as integer (+to_i+), it must be
  greater than or equal to 100.
  === The Headers
  The header must respond to +each+, and yield values of key and value.
+The header keys must be Strings.
  Special headers starting "rack." are for communicating with the
  server, and must not be sent back to the client.
-The header keys must be Strings.
  The header must not contain a +Status+ key.
  The header must conform to RFC7230 token specification, i.e. cannot
  contain non-printable ASCII, DQUOTE or "(),/:;<=>?@[\]{}".