diff --git a/.github/workflows/ci_sh_def.yml b/.github/workflows/ci_sh_def.yml
index a07e52a78..f9c3d6594 100644
--- a/.github/workflows/ci_sh_def.yml
+++ b/.github/workflows/ci_sh_def.yml
@@ -736,7 +736,7 @@ jobs:
 
         include:
           - python: 3.9
-            args: -DCMAKE_CXX_STANDARD=20 -DDOWNLOAD_EIGEN=OFF
+            args: -DCMAKE_CXX_STANDARD=20
           - python: 3.8
             args: -DCMAKE_CXX_STANDARD=17
 
@@ -860,7 +860,7 @@ jobs:
         cmake -S . -B build
         -DPYBIND11_WERROR=ON
         -DDOWNLOAD_CATCH=ON
-        -DDOWNLOAD_EIGEN=OFF
+        -DDOWNLOAD_EIGEN=ON
         -DCMAKE_CXX_STANDARD=20
         -DCMAKE_CXX_FLAGS="/GR /EHsc /DPYBIND11_USE_SMART_HOLDER_AS_DEFAULT"
 
diff --git a/.github/workflows/ci_sh_def.yml.patch b/.github/workflows/ci_sh_def.yml.patch
index 47ce22ee8..e221b107c 100644
--- a/.github/workflows/ci_sh_def.yml.patch
+++ b/.github/workflows/ci_sh_def.yml.patch
@@ -1,5 +1,5 @@
---- ci.yml	2022-02-14 18:01:36.161619977 -0800
-+++ ci_sh_def.yml	2022-02-14 18:02:00.307267865 -0800
+--- ci.yml	2022-02-16 07:15:34.785941659 -0800
++++ ci_sh_def.yml	2022-02-16 07:15:59.235610284 -0800
 @@ -1,4 +1,16 @@
 -name: CI
 +# PLEASE KEEP THIS GROUP OF FILES IN SYNC AT ALL TIMES:
@@ -145,7 +145,7 @@
      - uses: actions/checkout@v2
 @@ -838,6 +862,7 @@
          -DDOWNLOAD_CATCH=ON
-         -DDOWNLOAD_EIGEN=OFF
+         -DDOWNLOAD_EIGEN=ON
          -DCMAKE_CXX_STANDARD=20
 +        -DCMAKE_CXX_FLAGS="/GR /EHsc /DPYBIND11_USE_SMART_HOLDER_AS_DEFAULT"