diff --git a/cmake/config-ix.cmake b/cmake/config-ix.cmake
index d1e4b2a64ea..ca4af73d92c 100755
--- a/cmake/config-ix.cmake
+++ b/cmake/config-ix.cmake
@@ -486,7 +486,7 @@ set(LLVM_PREFIX ${CMAKE_INSTALL_PREFIX})
 
 if (LLVM_ENABLE_DOXYGEN)
   message(STATUS "Doxygen enabled.")
-  find_package(Doxygen)
+  find_package(Doxygen REQUIRED)
 
   if (DOXYGEN_FOUND)
     # If we find doxygen and we want to enable doxygen by default create a