diff --git a/tools/ci/test_build_system_cmake.sh b/tools/ci/test_build_system_cmake.sh
index 0e73339e0..41b820999 100755
--- a/tools/ci/test_build_system_cmake.sh
+++ b/tools/ci/test_build_system_cmake.sh
@@ -223,6 +223,21 @@ function run_tests()
     (grep '"command"' build/compile_commands.json | grep -v mfix-esp32-psram-cache-issue) && failure "All commands in compile_commands.json should use PSRAM cache workaround"
     mv sdkconfig.bak sdkconfig
 
+    print_status "Make sure a full build never runs '/usr/bin/env python' or similar"
+    OLDPATH="$PATH"
+    PYTHON="$(which python)"
+    rm -rf build
+    cat > ./python << EOF
+    #!/bin/sh
+    echo "The build system has executed '/usr/bin/env python' or similar"
+    exit 1
+EOF
+    chmod +x ./python
+    export PATH="$(pwd):$PATH"
+    ${PYTHON} $IDF_PATH/tools/idf.py build || failure "build failed"
+    export PATH="$OLDPATH"
+    rm ./python
+
     print_status "All tests completed"
     if [ -n "${FAILURES}" ]; then
         echo "Some failures were detected:"
diff --git a/tools/cmake/kconfig.cmake b/tools/cmake/kconfig.cmake
index 4eb132d96..8de088b68 100644
--- a/tools/cmake/kconfig.cmake
+++ b/tools/cmake/kconfig.cmake
@@ -129,7 +129,8 @@ function(kconfig_process_config)
         COMMAND ${CMAKE_COMMAND} -E env
         "COMPONENT_KCONFIGS=${kconfigs}"
         "COMPONENT_KCONFIGS_PROJBUILD=${kconfigs_projbuild}"
-        ${IDF_PATH}/tools/kconfig_new/confserver.py --kconfig ${IDF_PATH}/Kconfig --config ${SDKCONFIG}
+        ${PYTHON} ${IDF_PATH}/tools/kconfig_new/confserver.py
+        --kconfig ${IDF_PATH}/Kconfig --config ${SDKCONFIG}
         VERBATIM
         USES_TERMINAL)