diff --git a/llvm/cmake/modules/LLVMExternalProjectUtils.cmake b/llvm/cmake/modules/LLVMExternalProjectUtils.cmake
--- a/llvm/cmake/modules/LLVMExternalProjectUtils.cmake
+++ b/llvm/cmake/modules/LLVMExternalProjectUtils.cmake
@@ -344,6 +344,8 @@
                -DPACKAGE_VERSION=${PACKAGE_VERSION}
                -DCMAKE_BUILD_TYPE=${CMAKE_BUILD_TYPE}
                -DCMAKE_MAKE_PROGRAM=${CMAKE_MAKE_PROGRAM}
+               -DLLVM_ENABLE_SPHINX=${LLVM_ENABLE_SPHINX}
+               -DLLVM_BUILD_DOCS=${LLVM_BUILD_DOCS}
                -DCMAKE_EXPORT_COMPILE_COMMANDS=1
                ${cmake_args}
                ${PASSTHROUGH_VARIABLES}