diff --git a/CHANGELOG.md b/CHANGELOG.md
index f78c052..5240a1e 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -25,6 +25,12 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
   best-effort non-Ferrum fallback in `Injector#evaluate_axe` is kept but is now
   documented as unsupported/untested
   ([#31](https://github.com/Guided-Rails/axe-cuprite/issues/31)).
+- Documented that `AxeCuprite::Results` (and its nested wrappers) takes ownership
+  of the hash passed in and deep-freezes it **in place** — so a caller
+  constructing `Results.new(hash)` shouldn't pass or reuse a hash they intend to
+  mutate afterward. No behavior change; clarifies the existing read-only contract
+  in the `Results` doc comment and the README runner section
+  ([#33](https://github.com/Guided-Rails/axe-cuprite/issues/33)).
 
 ### Added
 - A unit test pinning the best-effort non-Ferrum fallback in
diff --git a/README.md b/README.md
index 427a854..8f9557c 100644
--- a/README.md
+++ b/README.md
@@ -149,6 +149,13 @@ on top of your configured defaults. Only `violations` and `incomplete` are
 carried back across the CDP boundary — the full results object (with
 `passes`/`inapplicable`) can be huge.
 
+`AxeCuprite::Results` is read-only: it **takes ownership of the hash it's given
+and deep-freezes it in place** (this backs the read-only `raw`/`to_h` contract).
+You normally get one straight from `Runner#run`, so this is transparent — but if
+you construct `Results.new(hash)` yourself, don't pass or keep a reference to a
+hash you intend to mutate afterward, or you'll hit a `FrozenError`. Dup it first
+if you need a mutable copy.
+
 ## Configuration
 
 ```ruby
diff --git a/lib/axe/cuprite/results.rb b/lib/axe/cuprite/results.rb
index ae6cae4..d4fb75f 100644
--- a/lib/axe/cuprite/results.rb
+++ b/lib/axe/cuprite/results.rb
@@ -26,6 +26,13 @@ def call(obj)
   #
   # The wrappers are read-only: `@raw` is deep-frozen at construction, so `raw`
   # and `to_h` expose the live underlying hash safely (callers cannot mutate it).
+  #
+  # Ownership note: `Results` (and the nested `Violation`/`Node`/`ContrastData`
+  # wrappers) **take ownership of the hash passed in and deep-freeze it in place**
+  # — they do not copy first. For the internal flow this is safe (the payload
+  # comes fresh off the CDP boundary), but if you construct `Results.new(hash)`
+  # yourself, don't pass — or hold onto — a hash you intend to mutate afterward,
+  # or you'll hit a `FrozenError`. Dup it first if you need a mutable copy.
   class Results
     attr_reader :raw