diff --git a/tests/CMakeLists.txt b/tests/CMakeLists.txt
index 82e84cb0..8accea98 100644
--- a/tests/CMakeLists.txt
+++ b/tests/CMakeLists.txt
@@ -124,7 +124,7 @@ if(MSVC) # MSVC or simulating MSVC
           >
         >
     )
-    check_cxx_compiler_flag("-Wno-reserved-identifier" WARN_RESERVED_ID)
+    check_cxx_compiler_flag("-Wreserved-identifier" WARN_RESERVED_ID)
     if (WARN_RESERVED_ID)
       target_compile_options(gsl_tests_config INTERFACE "-Wno-reserved-identifier")
     endif()
@@ -193,7 +193,7 @@ else()
         >
     )
 endif(MSVC)
-check_cxx_compiler_flag("-Wno-unsafe-buffer-usage" WARN_UNSAFE_BUFFER)
+check_cxx_compiler_flag("-Wunsafe-buffer-usage" WARN_UNSAFE_BUFFER)
 if (WARN_UNSAFE_BUFFER)
   # This test uses very greedy heuristics such as "no pointer arithmetic on raw buffer"
   target_compile_options(gsl_tests_config INTERFACE "-Wno-unsafe-buffer-usage")
@@ -260,7 +260,7 @@ if(MSVC) # MSVC or simulating MSVC
           >
         >
     )
-    check_cxx_compiler_flag("-Wno-reserved-identifier" WARN_RESERVED_ID)
+    check_cxx_compiler_flag("-Wreserved-identifier" WARN_RESERVED_ID)
     if (WARN_RESERVED_ID)
       target_compile_options(gsl_tests_config_noexcept INTERFACE "-Wno-reserved-identifier")
     endif()
@@ -305,7 +305,7 @@ else()
         >
     )
 endif(MSVC)
-check_cxx_compiler_flag("-Wno-unsafe-buffer-usage" WARN_UNSAFE_BUFFER)
+check_cxx_compiler_flag("-Wunsafe-buffer-usage" WARN_UNSAFE_BUFFER)
 if (WARN_UNSAFE_BUFFER)
   # This test uses very greedy heuristics such as "no pointer arithmetic on raw buffer"
   target_compile_options(gsl_tests_config_noexcept INTERFACE "-Wno-unsafe-buffer-usage")