diff --git a/cmake_modules/FindLibClang.cmake b/cmake_modules/FindLibClang.cmake
index 2eb0792..dab35df 100644
--- a/cmake_modules/FindLibClang.cmake
+++ b/cmake_modules/FindLibClang.cmake
@@ -16,6 +16,7 @@
 # most recent versions come first
 set(LIBCLANG_KNOWN_LLVM_VERSIONS 4.0.0
   4.0
+  3.9.1
   3.9.0
   3.9
   3.8.1