diff --git a/.github/workflows/core.yml b/.github/workflows/core.yml
index 445e6e0e..7b51b8be 100644
--- a/.github/workflows/core.yml
+++ b/.github/workflows/core.yml
@@ -25,7 +25,7 @@ jobs:
       - name: Install dependencies
         run: |
           python -m pip install --upgrade pip
-          pip install tox
+          pip install "tox<4"
 
       - name: Python Lint
         if: ${{ matrix.python-version != '3.6' }}
diff --git a/tests/commands/pkg/test_install.py b/tests/commands/pkg/test_install.py
index dcbd2d98..61ccde0d 100644
--- a/tests/commands/pkg/test_install.py
+++ b/tests/commands/pkg/test_install.py
@@ -443,7 +443,7 @@ def test_custom_project_libraries(
         )
         assert pkgs_to_specs(lm.get_installed()) == [
             PackageSpec("ArduinoJson@5.13.4"),
-            PackageSpec("Nanopb@0.4.6+4"),
+            PackageSpec("Nanopb@0.4.7"),
         ]
         assert config.get("env:devkit", "lib_deps") == [
             "bblanchon/ArduinoJson@^5",