diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index db47a263dbed..d42220561626 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -133,7 +133,7 @@ jobs:
           CARGO_TARGET_DIR: ${{ format('{0}/src/rust/target/', github.workspace) }}
       - name: Tests
         run: |
-            nox --no-install --  --color=yes --wycheproof-root=wycheproof ${{ matrix.PYTHON.NOXARGS }}
+            nox --no-install --  --color=yes --wycheproof-root=wycheproof --x509-limbo-root=x509-limbo ${{ matrix.PYTHON.NOXARGS }}
         env:
           NOXSESSION: ${{ matrix.PYTHON.NOXSESSION }}
           COLUMNS: 80
@@ -205,7 +205,7 @@ jobs:
           # OPENSSL_ENABLE_SHA1_SIGNATURES is for CentOS 9 Stream
           OPENSSL_ENABLE_SHA1_SIGNATURES: 1
           NOXSESSION: ${{ matrix.IMAGE.NOXSESSION }}
-      - run: '/venv/bin/nox --no-install --  --color=yes --wycheproof-root="wycheproof"'
+      - run: '/venv/bin/nox --no-install --  --color=yes --wycheproof-root="wycheproof" --x509-limbo-root="x509-limbo"'
         env:
           COLUMNS: 80
           # OPENSSL_ENABLE_SHA1_SIGNATURES is for CentOS 9 Stream
@@ -274,7 +274,7 @@ jobs:
           NOXSESSION: ${{ matrix.PYTHON.NOXSESSION }}
           CARGO_TARGET_DIR: ${{ format('{0}/src/rust/target/', github.workspace) }}
       - name: Tests
-        run: nox --no-install --  --color=yes --wycheproof-root=wycheproof
+        run: nox --no-install --  --color=yes --wycheproof-root=wycheproof --x509-limbo-root=x509-limbo
         env:
           NOXSESSION: ${{ matrix.PYTHON.NOXSESSION }}
           COLUMNS: 80
@@ -338,7 +338,7 @@ jobs:
           NOXSESSION: ${{ matrix.PYTHON.NOXSESSION }}
           CARGO_TARGET_DIR: ${{ format('{0}/src/rust/target/', github.workspace) }}
       - name: Tests
-        run: nox --no-install --  --color=yes --wycheproof-root=wycheproof
+        run: nox --no-install --  --color=yes --wycheproof-root=wycheproof --x509-limbo-root=x509-limbo
         env:
           NOXSESSION: ${{ matrix.PYTHON.NOXSESSION }}
           COLUMNS: 80
diff --git a/tests/conftest.py b/tests/conftest.py
index d99bb76c1913..d1f11abbb3c7 100644
--- a/tests/conftest.py
+++ b/tests/conftest.py
@@ -27,6 +27,7 @@ def pytest_report_header(config):
 
 def pytest_addoption(parser):
     parser.addoption("--wycheproof-root", default=None)
+    parser.addoption("--x509-limbo-root", default=None)
     parser.addoption("--enable-fips", default=False)