diff --git a/CMakeLists.txt b/CMakeLists.txt
index d6d43f51d772c103bea5508ea61edb8e9bd0eda0..9de412bbf0580f63be4ed65ca7c084e0002f2750 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -317,7 +317,7 @@ endif()
 
 #-----------------------------------------------------------------------------
 # Adjust compiler flags for some platforms.
-if(NOT CMAKE_COMPILER_IS_GNUCXX)
+if(NOT CMAKE_CXX_COMPILER_ID STREQUAL "GNU")
   if(CMAKE_SYSTEM MATCHES "OSF1-V.*")
     string(REGEX MATCH "-timplicit_local"
       KWSYS_CXX_FLAGS_HAVE_IMPLICIT_LOCAL "${CMAKE_CXX_FLAGS}")