diff --git a/compiler-rt/cmake/Modules/BuiltinTests.cmake b/compiler-rt/cmake/Modules/BuiltinTests.cmake
--- a/compiler-rt/cmake/Modules/BuiltinTests.cmake
+++ b/compiler-rt/cmake/Modules/BuiltinTests.cmake
@@ -46,7 +46,7 @@
 
   set(TRY_COMPILE_FLAGS "${ARG_FLAGS}")
   if(CMAKE_C_COMPILER_ID MATCHES Clang AND CMAKE_C_COMPILER_TARGET)
-    list(APPEND TRY_COMPILE_FLAGS "-target ${CMAKE_C_COMPILER_TARGET}")
+    list(APPEND TRY_COMPILE_FLAGS "--target=${CMAKE_C_COMPILER_TARGET}")
   endif()
 
   string(REPLACE ";" " " extra_flags "${TRY_COMPILE_FLAGS}")