1 files changed, 1 insertions, 1 deletions

diff --git a/SPEC.rdoc b/SPEC.rdoc
index 1270ae32..80219555 100644
--- a/SPEC.rdoc
+++ b/SPEC.rdoc
@@ -9,7 +9,7 @@ after to catch all mistakes.
 A Rack application is a Ruby object (not a class) that
 responds to +call+.
 It takes exactly one argument, the *environment*
-and returns an Array of exactly three values:
+and returns a non-frozen Array of exactly three values:
 The *status*,
 the *headers*,
 and the *body*.