diff --git a/cmake/Modules/HandleOutOfTreeLLVM.cmake b/cmake/Modules/HandleOutOfTreeLLVM.cmake
index 3bf5d601b..0e12c884e 100644
--- a/cmake/Modules/HandleOutOfTreeLLVM.cmake
+++ b/cmake/Modules/HandleOutOfTreeLLVM.cmake
@@ -77,6 +77,9 @@ if (CMAKE_SOURCE_DIR STREQUAL CMAKE_CURRENT_SOURCE_DIR)
   if (NOT DEFINED LLVM_INCLUDE_TESTS)
     set(LLVM_INCLUDE_TESTS ${LLVM_FOUND})
   endif()
+  if (NOT DEFINED LLVM_INCLUDE_DOCS)
+    set(LLVM_INCLUDE_DOCS ${LLVM_FOUND})
+  endif()
   if (NOT DEFINED LLVM_ENABLE_SPHINX)
     set(LLVM_ENABLE_SPHINX OFF)
   endif()