diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index bfe2c0f6b39..1efe6b06db1 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -555,7 +555,6 @@ jobs:
       - run: python3 -m nox -s test
 
   test-free-threaded:
-    if: ${{ contains(github.event.pull_request.labels.*.name, 'CI-build-full') || github.event_name != 'pull_request' }}
     needs: [fmt]
     runs-on: ubuntu-latest
     env:
diff --git a/noxfile.py b/noxfile.py
index 17ffb9aba85..f29bb45c109 100644
--- a/noxfile.py
+++ b/noxfile.py
@@ -5,6 +5,7 @@
 import shutil
 import subprocess
 import sys
+import sysconfig
 import tempfile
 from functools import lru_cache
 from glob import glob
@@ -32,6 +33,7 @@
 PYO3_DOCS_TARGET = PYO3_TARGET / "doc"
 PY_VERSIONS = ("3.7", "3.8", "3.9", "3.10", "3.11", "3.12", "3.13")
 PYPY_VERSIONS = ("3.9", "3.10")
+FREE_THREADED_BUILD = bool(sysconfig.get_config_var("Py_GIL_DISABLED"))
 
 
 @nox.session(venv_backend="none")
@@ -48,10 +50,14 @@ def test_rust(session: nox.Session):
     _run_cargo_test(session, package="pyo3-ffi")
 
     _run_cargo_test(session)
-    _run_cargo_test(session, features="abi3")
+    # the free-threaded build ignores abi3, so we skip abi3
+    # tests to avoid unnecessarily running the tests twice
+    if not FREE_THREADED_BUILD:
+        _run_cargo_test(session, features="abi3")
     if "skip-full" not in session.posargs:
         _run_cargo_test(session, features="full")
-        _run_cargo_test(session, features="abi3 full")
+        if not FREE_THREADED_BUILD:
+            _run_cargo_test(session, features="abi3 full")
 
 
 @nox.session(name="test-py", venv_backend="none")