diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 64a0258a..e8789628 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -281,11 +281,10 @@ jobs:
 
   pybind11-cmake:
     needs: [build-ubuntu, build-mac]
-    # strategy:
-    #   fail-fast: false
-    #   matrix:
-    #     python-version: [3.9]
-    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        platform: [ubuntu-20.04, ubuntu-latest]
+    runs-on: ${{ matrix.platform }}
     steps:
       - name: Checkout
         uses: actions/checkout@v2
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 460008e0..b123b89d 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -61,6 +61,15 @@ option(BUILD_PYTHON_BINDINGS "Build Python bindings with pybind11." OFF)
 option(BUILD_TESTING_PYTHON "Build Python tests only." OFF)
 
 if (BUILD_PYTHON_BINDINGS)
+  # In theory this is not required, as CMake selects the appropriate C++ standard
+  # However, as long as we support pybind11 < 2.6 we need to make sure that CMAKE_CXX_STANDARD
+  # is defined before   find_package(pybind11 REQUIRED)  to avoid that the CMake standard
+  # command line option is set by pybind11 via the PYBIND11_CPP_STANDARD variable, in a way that could
+  # interfere with CMake, see https://github.com/pybind/pybind11/blob/v2.4.3/tools/pybind11Tools.cmake#L21
+  if(NOT DEFINED CMAKE_CXX_STANDARD)
+    set(CMAKE_CXX_STANDARD 11)
+  endif()
+
   find_package(pybind11 REQUIRED)
   add_subdirectory(python)
 endif()
diff --git a/python/CMakeLists.txt b/python/CMakeLists.txt
index 47fcd19c..8dc3b4cd 100644
--- a/python/CMakeLists.txt
+++ b/python/CMakeLists.txt
@@ -1,4 +1,3 @@
-set(PYBIND11_CPP_STANDARD -std=c++11)
 pybind11_add_module(manifpy MODULE
   bindings_rn.cpp
   bindings_so2.cpp
@@ -13,8 +12,8 @@ target_link_libraries(manifpy PRIVATE ${PROJECT_NAME})
 # See e.g. https://pybind11.readthedocs.io/en/stable/advanced/cast/eigen.html#storage-orders
 target_compile_definitions(manifpy PRIVATE EIGEN_DEFAULT_TO_ROW_MAJOR)
 
-# Set required C++11 flag
-set_property(TARGET manifpy PROPERTY CXX_STANDARD 11)
+# Specify that C++11 features are required
+target_compile_features(manifpy PRIVATE cxx_nullptr)
 set_property(TARGET manifpy PROPERTY CXX_STANDARD_REQUIRED ON)
 set_property(TARGET manifpy PROPERTY CXX_EXTENSIONS OFF)