diff --git a/.github/workflows/pull_request_test.yml b/.github/workflows/pull_request_test.yml
index 95410d0..bedf62b 100644
--- a/.github/workflows/pull_request_test.yml
+++ b/.github/workflows/pull_request_test.yml
@@ -18,6 +18,8 @@ jobs:
         os: [ubuntu-22.04]
     steps:
     - uses: actions/checkout@v3
+      with:
+        submodules: true
     - name: Install dependencies
       run: |
         git clone https://gitlab.com/libeigen/eigen
@@ -51,6 +53,8 @@ jobs:
         os: [ubuntu-22.04]
     steps:
     - uses: actions/checkout@v3
+      with:
+        submodules: true
     - name: Install dependencies
       run: |
         git clone https://gitlab.com/libeigen/eigen
@@ -82,6 +86,8 @@ jobs:
         eigenversion: [3.3.4, 3.3.5, 3.3.6, 3.3.7, 3.3.8, 3.3.9, 3.4.0]
     steps:
     - uses: actions/checkout@v3
+      with:
+        submodules: true
     - name: Install dependencies
       run: |
         wget https://gitlab.com/libeigen/eigen/-/archive/${{ matrix.eigenversion }}/eigen-${{ matrix.eigenversion }}.tar.gz
@@ -112,6 +118,8 @@ jobs:
         eigenversion: [3.3.4, 3.3.5, 3.3.6, 3.3.7, 3.3.8, 3.3.9, 3.4.0]
     steps:
     - uses: actions/checkout@v3
+      with:
+        submodules: true
     - name: Install dependencies
       run: |
         Invoke-WebRequest -OutFile eigen.tar.gz https://gitlab.com/libeigen/eigen/-/archive/${{ matrix.eigenversion }}/eigen-${{ matrix.eigenversion }}.tar.gz
@@ -146,6 +154,8 @@ jobs:
         eigenversion: [3.4.0]
     steps:
     - uses: actions/checkout@v3
+      with:
+        submodules: true
     - name: Install dependencies
       run: |
         Invoke-WebRequest -OutFile eigen.tar.gz https://gitlab.com/libeigen/eigen/-/archive/${{ matrix.eigenversion }}/eigen-${{ matrix.eigenversion }}.tar.gz
@@ -177,6 +187,8 @@ jobs:
         os: [ubuntu-22.04, macOS-10.15, windows-2019]
     steps:        
     - uses: actions/checkout@v3
+      with:
+        submodules: true
     - name: Set up Python3
       uses: actions/setup-python@v1
       with:
diff --git a/.github/workflows/pull_request_test_non_x64.yml b/.github/workflows/pull_request_test_non_x64.yml
index 1aaee26..c02881c 100644
--- a/.github/workflows/pull_request_test_non_x64.yml
+++ b/.github/workflows/pull_request_test_non_x64.yml
@@ -17,6 +17,8 @@ jobs:
         eigenversion: [3.3.4, 3.3.5, 3.3.6, 3.3.7, 3.3.8, 3.3.9, 3.4.0]
     steps:
     - uses: actions/checkout@v3
+      with:
+        submodules: true
     - name: Install dependencies
       run: |
         wget https://gitlab.com/libeigen/eigen/-/archive/${{ matrix.eigenversion }}/eigen-${{ matrix.eigenversion }}.tar.gz