diff --git a/cmake/Findclang.cmake b/cmake/Findclang.cmake
index c556455d1c34e57b42764cfacaa6c87d68717c55..5f5bef8207c80a0e4185f9114f44217f07dfd990 100644
--- a/cmake/Findclang.cmake
+++ b/cmake/Findclang.cmake
@@ -48,7 +48,9 @@ else()
         /c/msys64/mingw64/lib
         c:\\msys64\\mingw64\\lib
     )
-    set(CLANG_LIBRARIES ${CLANG_LIBRARIES} ${CLANG_${_prettylibname_}_LIB})
+    if(CLANG_${_prettylibname_}_LIB)
+      set(CLANG_LIBRARIES ${CLANG_LIBRARIES} ${CLANG_${_prettylibname_}_LIB})
+    endif()
   endmacro(FIND_AND_ADD_CLANG_LIB)
 
   FIND_AND_ADD_CLANG_LIB(clangFrontendTool)