diff --git a/.github/workflows/tests-fast.yml b/.github/workflows/tests-fast.yml
index 8b0eed73..e6bec6b9 100644
--- a/.github/workflows/tests-fast.yml
+++ b/.github/workflows/tests-fast.yml
@@ -47,8 +47,17 @@ jobs:
             production.cloudflare.docker.com:443
             production.cloudfront.docker.com:443
       - uses: actions/checkout@v6
+        id: checkout
+        continue-on-error: true
         with:
           submodules: true
+      - name: 'nvmrc submodule fallback (forks without their own nvmrc)'
+        if: steps.checkout.outcome == 'failure'
+        shell: bash
+        run: |
+          git submodule set-url test/fixtures/nvmrc https://github.com/nvm-sh/nvmrc.git
+          git submodule sync --recursive
+          git submodule update --init --recursive
       - name: Install zsh, additional shells, and awk variant
         run: |
           sudo apt-get update
diff --git a/.github/workflows/tests-installation-iojs.yml b/.github/workflows/tests-installation-iojs.yml
index 3d0c37ec..941b9681 100644
--- a/.github/workflows/tests-installation-iojs.yml
+++ b/.github/workflows/tests-installation-iojs.yml
@@ -39,8 +39,17 @@ jobs:
             azure.archive.ubuntu.com:80
             packages.microsoft.com:443
       - uses: actions/checkout@v6
+        id: checkout
+        continue-on-error: true
         with:
           submodules: true
+      - name: 'nvmrc submodule fallback (forks without their own nvmrc)'
+        if: steps.checkout.outcome == 'failure'
+        shell: bash
+        run: |
+          git submodule set-url test/fixtures/nvmrc https://github.com/nvm-sh/nvmrc.git
+          git submodule sync --recursive
+          git submodule update --init --recursive
       - name: Install zsh and additional shells
         run: |
           sudo apt-get update
diff --git a/.github/workflows/tests-installation-node.yml b/.github/workflows/tests-installation-node.yml
index c1d44874..ef53c15f 100644
--- a/.github/workflows/tests-installation-node.yml
+++ b/.github/workflows/tests-installation-node.yml
@@ -45,8 +45,17 @@ jobs:
             registry-1.docker.io:443
             auth.docker.io:443
       - uses: actions/checkout@v6
+        id: checkout
+        continue-on-error: true
         with:
           submodules: true
+      - name: 'nvmrc submodule fallback (forks without their own nvmrc)'
+        if: steps.checkout.outcome == 'failure'
+        shell: bash
+        run: |
+          git submodule set-url test/fixtures/nvmrc https://github.com/nvm-sh/nvmrc.git
+          git submodule sync --recursive
+          git submodule update --init --recursive
       - uses: ljharb/actions/node/install@main
         name: 'npm install && version checks'
         with:
diff --git a/.github/workflows/tests-xenial.yml b/.github/workflows/tests-xenial.yml
index ed12b091..ca946c50 100644
--- a/.github/workflows/tests-xenial.yml
+++ b/.github/workflows/tests-xenial.yml
@@ -42,8 +42,17 @@ jobs:
             registry-1.docker.io:443
             auth.docker.io:443
       - uses: actions/checkout@v6
+        id: checkout
+        continue-on-error: true
         with:
           submodules: true
+      - name: 'nvmrc submodule fallback (forks without their own nvmrc)'
+        if: steps.checkout.outcome == 'failure'
+        shell: bash
+        run: |
+          git submodule set-url test/fixtures/nvmrc https://github.com/nvm-sh/nvmrc.git
+          git submodule sync --recursive
+          git submodule update --init --recursive
       - uses: ljharb/actions/node/install@main
         name: 'npm install && version checks'
         with: