diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 46ad906..87de2eb 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -100,6 +100,18 @@ jobs:
           uvx ty check test_types.py
           rm test_types.py
           echo "✅ Type checker integration working"
+
+      - name: Smoke test the wheel in an empty environment
+        # The dev environment carries packages the wheel does not declare (mypy pulls
+        # in typing_extensions, for example), so an undeclared runtime import only
+        # shows up in an install that has nothing but the wheel and its dependencies.
+        run: |
+          uv run maturin build --release --out smoke-dist
+          uv venv --no-project --python "$(uv run python -c 'import sys; print(sys.executable)')" smoke-venv
+          uv pip install --python smoke-venv/bin/python smoke-dist/*.whl
+          smoke-venv/bin/python -c "import cel; assert cel.evaluate('1 + 1') == 2"
+          smoke-venv/bin/cel '1 + 2'
+          smoke-venv/bin/cel --version
   linux:
     runs-on: ${{ matrix.platform.runner }}
     needs: [test, lint]
diff --git a/CHANGELOG.md b/CHANGELOG.md
index b2f1696..8f83829 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -17,6 +17,16 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Fixed
 
+- **`import cel` failed in a clean install.** `cel.cli` imported `Annotated` from
+  `typing_extensions`, which is not one of this package's declared dependencies. It
+  used to arrive transitively through Typer, but Typer 0.21.2 (February 2026) dropped
+  that dependency, so `pip install common-expression-language` into an environment
+  with nothing else in it left `import cel` raising `ModuleNotFoundError`. The
+  development lockfile masked this because mypy still pulls `typing_extensions` in.
+  `Annotated` now comes from the standard library (`typing`), which has provided it
+  since Python 3.9. CI now installs the built wheel into an empty virtual environment
+  and imports the package and runs the `cel` command, so an undeclared runtime
+  dependency fails the build.
 - The type stubs (`cel.pyi`) now use the parameter names the runtime actually
   accepts: `evaluate(src, evaluation_context)` rather than `(expression, context)`,
   and `Context.add_function(name, function)` rather than `func`. A keyword call
diff --git a/python/cel/cli.py b/python/cel/cli.py
index 22ea1e1..216cc38 100644
--- a/python/cel/cli.py
+++ b/python/cel/cli.py
@@ -16,7 +16,7 @@
 import time
 from importlib.metadata import PackageNotFoundError, version
 from pathlib import Path
-from typing import Any, Dict, Optional, Tuple
+from typing import Annotated, Any, Dict, Optional, Tuple
 
 import typer
 
@@ -35,7 +35,6 @@
 from rich.panel import Panel
 from rich.syntax import Syntax
 from rich.table import Table
-from typing_extensions import Annotated
 
 # Import directly from relative modules to avoid circular imports
 from .cel import Context, evaluate