diff --git a/CMakeLists.txt b/CMakeLists.txt
index 8e890830..1c030dcf 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -508,7 +508,7 @@ upx_print_var(CMAKE_C_COMPILER CMAKE_CXX_COMPILER CMAKE_AR CMAKE_RANLIB)
 upx_print_var(CMAKE_C_COMPILER_ID CMAKE_C_COMPILER_VERSION CMAKE_C_COMPILER_FRONTEND_VARIANT CMAKE_C_COMPILER_ARCHITECTURE_ID CMAKE_C_PLATFORM_ID CMAKE_C_COMPILER_ABI)
 upx_print_var(CMAKE_CXX_COMPILER_ID CMAKE_CXX_COMPILER_VERSION CMAKE_CXX_COMPILER_FRONTEND_VARIANT CMAKE_CXX_COMPILER_ARCHITECTURE_ID CMAKE_CXX_PLATFORM_ID CMAKE_CXX_COMPILER_ABI)
 upx_print_var(CMAKE_INTERPROCEDURAL_OPTIMIZATION CMAKE_POSITION_INDEPENDENT_CODE CMAKE_TRY_COMPILE_CONFIGURATION)
-upx_print_var(APPLE CYGWIN GNUC MINGW MSVC MSVC_FRONTEND MSVC_IDE UNIX WIN32 WIN64)
+upx_print_var(APPLE CLANG CYGWIN GNUC MINGW MSVC MSVC_FRONTEND MSVC_IDE UNIX WIN32 WIN64)
 endif() # UPX_CONFIG_CMAKE_DISABLE_PRINT_INFO
 upx_print_var(CMAKE_INSTALL_PREFIX CMAKE_CONFIGURATION_TYPES CMAKE_BUILD_TYPE)
 if(Threads_FOUND)
diff --git a/misc/cmake/functions.cmake b/misc/cmake/functions.cmake
index 6e18c1f2..4389eac3 100644
--- a/misc/cmake/functions.cmake
+++ b/misc/cmake/functions.cmake
@@ -293,8 +293,12 @@ function(upx_sanitize_target) # ARGV
         elseif(MINGW OR CYGWIN)
             # avoid link errors with current MinGW-w64 versions
             # see https://www.mingw-w64.org/contribute/#sanitizers-asan-tsan-usan
+        elseif(CMAKE_C_COMPILER_ID MATCHES "^Clang$" AND CMAKE_C_COMPILER_VERSION VERSION_LESS "9.0")
+            # unreliable/broken sanitize implementation before clang-9 (Sep 2019)
+            message(WARNING "WARNING: ignoring SANITIZE for target '${t}'")
         elseif(CMAKE_C_COMPILER_ID MATCHES "^GNU" AND CMAKE_C_COMPILER_VERSION VERSION_LESS "8.0")
-            # unsupported compiler; unreliable/broken sanitize implementation
+            # unsupported compiler; unreliable/broken sanitize implementation before gcc-8 (May 2018)
+            message(WARNING "WARNING: ignoring SANITIZE for target '${t}'")
         else()
             # default sanitizer for Debug builds
             target_compile_options(${t} PRIVATE $<$<CONFIG:Debug>:-fsanitize=undefined -fsanitize-undefined-trap-on-error -fstack-protector-all>)
diff --git a/src/check/dt_check.cpp b/src/check/dt_check.cpp
index a55c57d2..717c2d56 100644
--- a/src/check/dt_check.cpp
+++ b/src/check/dt_check.cpp
@@ -384,14 +384,6 @@ static noinline bool shall_test_float_division_by_zero(void) {
 #if defined(__clang__) && defined(__FAST_MATH__) && defined(__INTEL_LLVM_COMPILER)
             // warning: comparison with NaN always evaluates to false in fast floating point modes
             fprintf(stderr, "upx: WARNING: ignoring %s: __FAST_MATH__\n", envvar);
-#elif defined(__clang__) && (__clang_major__ < 9) && defined(__SANITIZE_UNDEFINED_BEHAVIOR__)
-            // UBSAN problem with clang < 9
-            // @COMPILER_BUG @CLANG_BUG @UBSAN_BUG
-            fprintf(stderr, "upx: WARNING: ignoring %s: UBSAN\n", envvar);
-#elif defined(__clang__) && (__clang_major__ < 8)
-            // NOTE: cannot reliably detect __SANITIZE_UNDEFINED_BEHAVIOR__ on older clang versions
-            // @COMPILER_BUG @CLANG_BUG @UBSAN_BUG
-            fprintf(stderr, "upx: WARNING: ignoring %s: clang %d\n", envvar, __clang_major__);
 #else
             result = true;
 #endif