diff --git a/pack/CMakeLists.txt b/pack/CMakeLists.txt
index 7d8c2ee0..a107a0c7 100644
--- a/pack/CMakeLists.txt
+++ b/pack/CMakeLists.txt
@@ -226,7 +226,7 @@ elseif(WIN32)
   set(CPACK_NSIS_EXECUTABLES_DIRECTORY ".")
   set(CPACK_NSIS_MUI_FINISHPAGE_RUN ${GITTYUP_NAME}.exe)
 
-  if(CMAKE_CL_64)
+  if(CMAKE_SIZEOF_VOID_P EQUAL 8)
     install(
       FILES ${RSRC_DIR}/vcredist_x64.exe
       DESTINATION .