diff --git a/ci.sh b/ci.sh
index 9362dbc72..cd1ce42e8 100755
--- a/ci.sh
+++ b/ci.sh
@@ -58,6 +58,8 @@ else
     flags=""
 fi
 
+python -m uv pip install https://github.com/graingert/outcome/archive/refs/heads/invalid-objects-on-unwrap.zip
+
 # If we're testing with a LSP installed, then it might break network
 # stuff, so wait until after we've finished setting everything else
 # up.
diff --git a/src/trio/_tests/test_trio.py b/src/trio/_tests/test_trio.py
index 65d4ce34f..c038a2088 100644
--- a/src/trio/_tests/test_trio.py
+++ b/src/trio/_tests/test_trio.py
@@ -6,3 +6,15 @@ def test_trio_import() -> None:
             del sys.modules[module]
 
     import trio  # noqa: F401
+
+
+def test_we_have_peek() -> None:
+    """
+    temporary test to see if we are running on outcome v2
+    """
+    import outcome
+
+    def fn() -> int:
+        return 1
+
+    assert outcome.capture(fn).peek() == 1
diff --git a/tox.ini b/tox.ini
index 11bd09d0c..825e52f06 100644
--- a/tox.ini
+++ b/tox.ini
@@ -102,6 +102,7 @@ description = "Run type checks: mypy on all platforms, and pyright on `src/trio[
 deps =
     -r test-requirements.txt
     exceptiongroup
+    https://github.com/graingert/outcome/archive/refs/heads/invalid-objects-on-unwrap.zip
 base_python = 3.10
 set_env =
     PYRIGHT_PYTHON_IGNORE_WARNINGS=1