diff --git a/tests/CMakeLists.txt b/tests/CMakeLists.txt
index 8c81b9123..40a97d3b0 100644
--- a/tests/CMakeLists.txt
+++ b/tests/CMakeLists.txt
@@ -10,7 +10,6 @@ set(JSON_32bitTest     AUTO CACHE STRING "Enable the 32bit unit test (ON/OFF/AUT
 set(JSON_TestStandards "" CACHE STRING "The list of standards to test explicitly.")
 
 # using an env var, since this will also affect targets executing cmake (such as "ci_test_compiler_default")
-set(JSON_FORCED_GLOBAL_COMPILE_OPTIONS $ENV{JSON_FORCED_GLOBAL_COMPILE_OPTIONS})
 if (NOT "" STREQUAL "$ENV{JSON_FORCED_GLOBAL_COMPILE_OPTIONS}")
     add_compile_options($ENV{JSON_FORCED_GLOBAL_COMPILE_OPTIONS})
 endif()
diff --git a/tests/cmake_add_subdirectory/CMakeLists.txt b/tests/cmake_add_subdirectory/CMakeLists.txt
index 7bb661075..0b82d9141 100644
--- a/tests/cmake_add_subdirectory/CMakeLists.txt
+++ b/tests/cmake_add_subdirectory/CMakeLists.txt
@@ -1,6 +1,8 @@
 add_test(NAME cmake_add_subdirectory_configure
   COMMAND ${CMAKE_COMMAND}
     -G "${CMAKE_GENERATOR}"
+    -A "${CMAKE_GENERATOR_PLATFORM}"
+    -T "${CMAKE_GENERATOR_TOOLSET}"
     -DCMAKE_CXX_COMPILER=${CMAKE_CXX_COMPILER}
     -DCMAKE_CXX_FLAGS=${CMAKE_CXX_FLAGS}
     -Dnlohmann_json_source=${PROJECT_SOURCE_DIR}
diff --git a/tests/cmake_fetch_content/CMakeLists.txt b/tests/cmake_fetch_content/CMakeLists.txt
index 42fcb5816..4e819d51f 100644
--- a/tests/cmake_fetch_content/CMakeLists.txt
+++ b/tests/cmake_fetch_content/CMakeLists.txt
@@ -1,9 +1,10 @@
 add_test(NAME cmake_fetch_content_configure
   COMMAND ${CMAKE_COMMAND}
     -G "${CMAKE_GENERATOR}"
+    -A "${CMAKE_GENERATOR_PLATFORM}"
+    -T "${CMAKE_GENERATOR_TOOLSET}"
     -DCMAKE_CXX_COMPILER=${CMAKE_CXX_COMPILER}
     -DCMAKE_CXX_FLAGS=${CMAKE_CXX_FLAGS}
-    -Dnlohmann_json_source=${PROJECT_SOURCE_DIR}
     ${CMAKE_CURRENT_SOURCE_DIR}/project
 )
 add_test(NAME cmake_fetch_content_build
diff --git a/tests/cmake_fetch_content2/CMakeLists.txt b/tests/cmake_fetch_content2/CMakeLists.txt
index 9b24fee01..98411bf5a 100644
--- a/tests/cmake_fetch_content2/CMakeLists.txt
+++ b/tests/cmake_fetch_content2/CMakeLists.txt
@@ -2,9 +2,10 @@ if (${CMAKE_VERSION} VERSION_GREATER_EQUAL "3.14")
   add_test(NAME cmake_fetch_content2_configure
     COMMAND ${CMAKE_COMMAND}
     -G "${CMAKE_GENERATOR}"
+    -A "${CMAKE_GENERATOR_PLATFORM}"
+    -T "${CMAKE_GENERATOR_TOOLSET}"
     -DCMAKE_CXX_COMPILER=${CMAKE_CXX_COMPILER}
     -DCMAKE_CXX_FLAGS=${CMAKE_CXX_FLAGS}
-    -Dnlohmann_json_source=${PROJECT_SOURCE_DIR}
     ${CMAKE_CURRENT_SOURCE_DIR}/project
   )
   add_test(NAME cmake_fetch_content2_build
diff --git a/tests/cmake_import/CMakeLists.txt b/tests/cmake_import/CMakeLists.txt
index eec526389..9acea845d 100644
--- a/tests/cmake_import/CMakeLists.txt
+++ b/tests/cmake_import/CMakeLists.txt
@@ -2,6 +2,7 @@ add_test(NAME cmake_import_configure
   COMMAND ${CMAKE_COMMAND}
     -G "${CMAKE_GENERATOR}"
     -A "${CMAKE_GENERATOR_PLATFORM}"
+    -T "${CMAKE_GENERATOR_TOOLSET}"
     -DCMAKE_CXX_COMPILER=${CMAKE_CXX_COMPILER}
     -DCMAKE_CXX_FLAGS=${CMAKE_CXX_FLAGS}
     -Dnlohmann_json_DIR=${PROJECT_BINARY_DIR}
diff --git a/tests/cmake_import_minver/CMakeLists.txt b/tests/cmake_import_minver/CMakeLists.txt
index 42e3ff3e4..029789267 100644
--- a/tests/cmake_import_minver/CMakeLists.txt
+++ b/tests/cmake_import_minver/CMakeLists.txt
@@ -2,6 +2,7 @@ add_test(NAME cmake_import_minver_configure
   COMMAND ${CMAKE_COMMAND}
     -G "${CMAKE_GENERATOR}"
     -A "${CMAKE_GENERATOR_PLATFORM}"
+    -T "${CMAKE_GENERATOR_TOOLSET}"
     -DCMAKE_CXX_COMPILER=${CMAKE_CXX_COMPILER}
     -DCMAKE_CXX_FLAGS=${CMAKE_CXX_FLAGS}
     -Dnlohmann_json_DIR=${PROJECT_BINARY_DIR}
diff --git a/tests/cmake_target_include_directories/CMakeLists.txt b/tests/cmake_target_include_directories/CMakeLists.txt
index 86fea3a5a..fac888e0f 100644
--- a/tests/cmake_target_include_directories/CMakeLists.txt
+++ b/tests/cmake_target_include_directories/CMakeLists.txt
@@ -1,6 +1,8 @@
 add_test(NAME cmake_target_include_directories_configure
   COMMAND ${CMAKE_COMMAND}
     -G "${CMAKE_GENERATOR}"
+    -A "${CMAKE_GENERATOR_PLATFORM}"
+    -T "${CMAKE_GENERATOR_TOOLSET}"
     -DCMAKE_CXX_COMPILER=${CMAKE_CXX_COMPILER}
     -DCMAKE_CXX_FLAGS=${CMAKE_CXX_FLAGS}
     -Dnlohmann_json_source=${PROJECT_SOURCE_DIR}