diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index f10404dcd..0f156fbc4 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -576,7 +576,7 @@ jobs:
       matrix:
         centos:
           - 7  # GCC 4.8
-          # BROKEN_2021-06-03 - 8
+          - 8
 
     name: "🐍 3 • CentOS ${{ matrix.centos }} • x64"
     container: "centos:${{ matrix.centos }}"
diff --git a/.github/workflows/ci_sh_def.yml b/.github/workflows/ci_sh_def.yml
index 2e42cb7a9..b4da91128 100644
--- a/.github/workflows/ci_sh_def.yml
+++ b/.github/workflows/ci_sh_def.yml
@@ -594,7 +594,7 @@ jobs:
       matrix:
         centos:
           - 7  # GCC 4.8
-          # BROKEN_2021-06-03 - 8
+          - 8
 
     name: "🐍 3 • CentOS ${{ matrix.centos }} • x64"
     container: "centos:${{ matrix.centos }}"
@@ -611,10 +611,21 @@ jobs:
     - name: Install dependencies
       run: python3 -m pip install cmake -r tests/requirements.txt --prefer-binary
 
+    - name: VAR_BUILD_TYPE 7
+      if: matrix.centos == 7
+      run: echo Release > VAR_BUILD_TYPE
+
+    # Using Debug to avoid segfault that appeared around 2021-06-04,
+    # apparently when the gcc version changed from 8.3 to 8.4.
+    - name: VAR_BUILD_TYPE 8
+      if: matrix.centos == 8
+      run: echo Debug > VAR_BUILD_TYPE
+
     - name: Configure
       shell: bash
       run: >
         cmake -S . -B build
+        -DCMAKE_BUILD_TYPE=$(cat VAR_BUILD_TYPE)
         -DPYBIND11_WERROR=ON
         -DDOWNLOAD_CATCH=ON
         -DDOWNLOAD_EIGEN=ON
diff --git a/.github/workflows/ci_sh_def.yml.patch b/.github/workflows/ci_sh_def.yml.patch
index 4dad0786a..8d019e595 100644
--- a/.github/workflows/ci_sh_def.yml.patch
+++ b/.github/workflows/ci_sh_def.yml.patch
@@ -1,5 +1,5 @@
---- ci.yml	2021-05-27 11:30:03.442224943 -0700
-+++ ci_sh_def.yml	2021-05-27 11:30:42.672719066 -0700
+--- ci.yml	2021-06-18 01:41:07.246849382 -0700
++++ ci_sh_def.yml	2021-06-18 01:41:47.114491643 -0700
 @@ -1,4 +1,15 @@
 -name: CI-SH-AVL
 +# PLEASE KEEP THIS GROUP OF FILES IN SYNC AT ALL TIMES:
@@ -84,7 +84,7 @@
          -DCMAKE_CXX_COMPILER=$(which icpc)  \
          -DPYTHON_EXECUTABLE=$(python3 -c "import sys; print(sys.executable)")
  
-@@ -601,6 +619,7 @@
+@@ -612,6 +630,7 @@
          -DDOWNLOAD_CATCH=ON
          -DDOWNLOAD_EIGEN=ON
          -DCMAKE_CXX_STANDARD=11
@@ -92,7 +92,7 @@
          -DPYTHON_EXECUTABLE=$(python3 -c "import sys; print(sys.executable)")
  
      - name: Build
-@@ -651,6 +670,7 @@
+@@ -662,6 +681,7 @@
          cmake ../pybind11-tests
          -DDOWNLOAD_CATCH=ON
          -DPYBIND11_WERROR=ON
@@ -100,7 +100,7 @@
          -DPYTHON_EXECUTABLE=$(python3 -c "import sys; print(sys.executable)")
        working-directory: /build-tests
  
-@@ -746,6 +766,7 @@
+@@ -757,6 +777,7 @@
          -DPYBIND11_WERROR=ON
          -DDOWNLOAD_CATCH=ON
          -DDOWNLOAD_EIGEN=ON
@@ -108,7 +108,7 @@
          ${{ matrix.args }}
      - name: Build C++11
        run: cmake --build build -j 2
-@@ -792,6 +813,7 @@
+@@ -803,6 +824,7 @@
          -DPYBIND11_WERROR=ON
          -DDOWNLOAD_CATCH=ON
          -DDOWNLOAD_EIGEN=ON
@@ -116,7 +116,7 @@
  
      - name: Build C++14
        run: cmake --build build -j 2
-@@ -812,12 +834,13 @@
+@@ -823,12 +845,13 @@
            - 3.7
          std:
            - 14