diff --git a/.flake8 b/.flake8
index 4599eaac..72bac135 100644
--- a/.flake8
+++ b/.flake8
@@ -7,3 +7,4 @@ exclude = .git,__pycache__,.nox,docs/source/conf.py,old,build,dist,configs/ipyth
 per-file-ignores =
     # imported but unused
     __init__.py: F401
+    scripts/check_toolkit_imports.py: F401
diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index aca103a0..76660374 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -433,6 +433,46 @@ jobs:
           path: coverage-data/coverage.xml
           retention-days: 30
 
+  # Other jobs take the toolkit's dependencies from poetry.lock; this one resolves
+  # the wheel's own requirements, as `pip install deepnote-toolkit` does for users.
+  wheel-install-check:
+    name: Wheel Install Check - Python ${{ matrix.python-version }}
+    runs-on: ubuntu-latest
+    timeout-minutes: 15
+    strategy:
+      fail-fast: false
+      matrix:
+        python-version: ["3.10", "3.11", "3.12", "3.13", "3.14"]
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@08eba0b27e820071cde6df949e0beb9ba4906955 # v4
+        with:
+          fetch-depth: 0
+          fetch-tags: true
+          persist-credentials: false
+
+      - name: Set up Python ${{ matrix.python-version }}
+        uses: actions/setup-python@a26af69be951a213d495a4c3e4e4022e16d87065 # v5
+        with:
+          python-version: ${{ matrix.python-version }}
+
+      - name: Install Poetry
+        uses: snok/install-poetry@76e04a911780d5b312d89783f7b1cd627778900a # v1
+        with:
+          version: ${{ env.POETRY_VERSION }}
+
+      - name: Build wheel
+        id: build
+        uses: ./.github/actions/build-wheel
+
+      - name: Install wheel without the lock and import the toolkit
+        env:
+          WHEEL_PATH: ${{ steps.build.outputs.wheel-path }}
+        run: |
+          python -m venv /tmp/smoke
+          /tmp/smoke/bin/python -m pip install "${WHEEL_PATH}[server]"
+          /tmp/smoke/bin/python scripts/check_toolkit_imports.py
+
   audit-prod:
     name: Audit - Production
     runs-on: ubuntu-latest
diff --git a/poetry.lock b/poetry.lock
index ef5df170..c4b784c6 100644
--- a/poetry.lock
+++ b/poetry.lock
@@ -9458,4 +9458,4 @@ server = ["deepnote-python-lsp-server", "jupyter-resource-usage", "jupyter-serve
 [metadata]
 lock-version = "2.1"
 python-versions = ">=3.10.0,<3.15"
-content-hash = "04a325f38a272beccf64959c3054ef9764fcbc230fcf8f2c6ce1aa57e94977aa"
+content-hash = "7c9e1e2316e450b768c48877b533b5b5ad2399666880f5d236c40fb89d3197ff"
diff --git a/pyproject.toml b/pyproject.toml
index 636e11ef..d78bee64 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -68,7 +68,8 @@ dependencies = [
     "pyarrow>=16.0.0,<18.0.0; python_version == '3.10' and sys_platform == 'darwin'",
     "pyarrow>=13.0.0,<=17.0.0; python_version == '3.11' and sys_platform != 'darwin'",
     "pyarrow>=16.0.0,<=18.0.0; python_version == '3.11' and sys_platform == 'darwin'",
-    "pyarrow>=23.0.1; python_version == '3.12'",  # 23.0.1 patches CVE-2026-25087 (GHSA-rgxp-2hwp-jwgg)
+    # pyarrow 26 requires NumPy 2 at import time without declaring it, and 3.12 is on numpy<2.
+    "pyarrow>=23.0.1,<26; python_version == '3.12'",
     "pyarrow>=23.0.1; python_version >= '3.13'",  # 3.10/3.11 stay <17 via databricks-sqlalchemy 1.x (SQLAlchemy 1.x compat)
 
     "db-dtypes>=1.2.0,<1.4",
diff --git a/scripts/check_toolkit_imports.py b/scripts/check_toolkit_imports.py
new file mode 100644
index 00000000..052d13e2
--- /dev/null
+++ b/scripts/check_toolkit_imports.py
@@ -0,0 +1,32 @@
+"""Import every name deepnote_toolkit/__init__.py loads, so a broken dependency fails."""
+
+import deepnote_toolkit
+from deepnote_toolkit import artifacts, experimental_components, ocelots
+from deepnote_toolkit.artifacts import delete_dataframe, store_dataframe
+from deepnote_toolkit.chart import DeepnoteChart
+from deepnote_toolkit.dataframe_utils import browse_dataframe
+from deepnote_toolkit.execute_post_start_hooks import execute_post_start_hooks
+from deepnote_toolkit.notebook_functions import (
+    cancel_notebook_function,
+    export_last_block_result,
+    run_notebook_function,
+)
+from deepnote_toolkit.runtime_initialization import init_deepnote_runtime
+from deepnote_toolkit.session_persistence import (
+    persist_notebook_session,
+    restore_notebook_session,
+)
+from deepnote_toolkit.set_integrations_env import set_integration_env
+from deepnote_toolkit.set_notebook_path import set_notebook_path
+from deepnote_toolkit.sql.query_preview import DeepnoteQueryPreview
+from deepnote_toolkit.sql.sql_execution import (
+    execute_sql,
+    execute_sql_with_connection_json,
+)
+from deepnote_toolkit.variable_explorer import (
+    deepnote_export_df,
+    deepnote_get_data_preview_json,
+    get_var_list,
+)
+
+print(f"Imported deepnote_toolkit from {deepnote_toolkit.__file__}")