Index: llvm/trunk/cmake/modules/HandleLLVMOptions.cmake
===================================================================
--- llvm/trunk/cmake/modules/HandleLLVMOptions.cmake
+++ llvm/trunk/cmake/modules/HandleLLVMOptions.cmake
@@ -686,8 +686,8 @@
 # lld doesn't print colored diagnostics when invoked from Ninja
 if (UNIX AND CMAKE_GENERATOR STREQUAL "Ninja")
   include(CheckLinkerFlag)
-  check_linker_flag("-Wl,-color-diagnostics" LINKER_SUPPORTS_COLOR_DIAGNOSTICS)
-  append_if(LINKER_SUPPORTS_COLOR_DIAGNOSTICS "-Wl,-color-diagnostics"
+  check_linker_flag("-Wl,--color-diagnostics" LINKER_SUPPORTS_COLOR_DIAGNOSTICS)
+  append_if(LINKER_SUPPORTS_COLOR_DIAGNOSTICS "-Wl,--color-diagnostics"
     CMAKE_EXE_LINKER_FLAGS CMAKE_MODULE_LINKER_FLAGS CMAKE_SHARED_LINKER_FLAGS)
 endif()