diff --git a/CMake/Macros.cmake b/CMake/Macros.cmake
index a0c26d483b..5e26c38469 100644
--- a/CMake/Macros.cmake
+++ b/CMake/Macros.cmake
@@ -40,20 +40,12 @@ set(CURL_TEST_DEFINES "")  # Initialize global variable
 # Return result in variable: CURL_TEST_OUTPUT
 macro(curl_internal_test _curl_test)
   if(NOT DEFINED "${_curl_test}")
-    string(REPLACE ";" " " _cmake_required_definitions "${CMAKE_REQUIRED_DEFINITIONS}")
-    set(_curl_test_add_libraries "")
-    if(CMAKE_REQUIRED_LIBRARIES)
-      set(_curl_test_add_libraries
-        "-DLINK_LIBRARIES:STRING=${CMAKE_REQUIRED_LIBRARIES}")
-    endif()
-
     message(STATUS "Performing Test ${_curl_test}")
     try_compile(${_curl_test}
       ${PROJECT_BINARY_DIR}
       "${CMAKE_CURRENT_SOURCE_DIR}/CMake/CurlTests.c"
-      CMAKE_FLAGS
-        "-DCOMPILE_DEFINITIONS:STRING=-D${_curl_test} ${CURL_TEST_DEFINES} ${CMAKE_REQUIRED_FLAGS} ${_cmake_required_definitions}"
-        "${_curl_test_add_libraries}"
+      COMPILE_DEFINITIONS "-D${_curl_test}" ${CURL_TEST_DEFINES} ${CMAKE_REQUIRED_FLAGS} ${CMAKE_REQUIRED_DEFINITIONS}
+      LINK_LIBRARIES "${CMAKE_REQUIRED_LIBRARIES}"
       OUTPUT_VARIABLE CURL_TEST_OUTPUT)
     if(${_curl_test})
       set(${_curl_test} 1 CACHE INTERNAL "curl test")
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 88a4c29e35..60014108ce 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1557,7 +1557,7 @@ foreach(_variable IN ITEMS
     HAVE_UNISTD_H
 )
   if(${_variable})
-    string(APPEND CURL_TEST_DEFINES " -D${_variable}")
+    list(APPEND CURL_TEST_DEFINES "-D${_variable}")
   endif()
 endforeach()