diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
index a6bec562ea..f7aecd71e7 100644
--- a/.github/workflows/tests.yml
+++ b/.github/workflows/tests.yml
@@ -59,9 +59,9 @@ jobs:
         run: |
           python -m pip install poetry-dynamic-versioning[plugin]
       # Install test dependencies (tox) to the root (non-package install)
-      # - name: Install test dependencies
-      #   run: |
-      #     poetry install --no-root --only test
+      - name: Install test dependencies
+        run: |
+          poetry install --no-root --only test
       - name: set full Python version in PY env var
         if: ${{ matrix.os != 'windows-latest' }}
         # See https://pre-commit.com/#github-actions-example
@@ -73,10 +73,8 @@ jobs:
           node-version: 18.x
       - name: Install Yarn
         run: npm install -g yarn
-      - name: Run tox testsa
-        run: |
-          pip install tox
-          tox -e ${{ matrix.tox }}
+      - name: Run tox tests
+        run: tox -e ${{ matrix.tox }}
 
   lint_typecheck_test_webui:
     runs-on: ubuntu-latest
diff --git a/tox.ini b/tox.ini
index b3667d576a..77e29e4057 100644
--- a/tox.ini
+++ b/tox.ini
@@ -1,4 +1,5 @@
 [tox]
+isolated_build = True
 skipsdist = True
 envlist =
     ruff
@@ -16,7 +17,7 @@ allowlist_externals =
     make
 commands =
     poetry install --with test
-    python -m unittest discover []
+    poetry run python -m unittest discover []
     ; Disable these tests for now, because they are breaking. When someone has time they should be converted into regular unit tests
     ; bash -ec "PYTHONUNBUFFERED=1 timeout 20s python3 examples/rest.py >{temp_dir}/out.txt 2>/{temp_dir}/err.txt || true"
     ; grep -qm 1 'my custom error message with response text, response was {"args"' {temp_dir}/out.txt
@@ -27,7 +28,7 @@ commands =
 [testenv:fail_fast_test_main]
 commands = 
     poetry install --with test
-    python -m unittest -f locust.test.test_main
+    poetry run python -m unittest -f locust.test.test_main
 
 [testenv:ruff]
 ; Pin the same version in the .pre-commit-config.yaml file.