diff --git a/clang/docs/ThinLTO.rst b/clang/docs/ThinLTO.rst
--- a/clang/docs/ThinLTO.rst
+++ b/clang/docs/ThinLTO.rst
@@ -213,7 +213,7 @@
    <https://llvm.org/docs/CMake.html#options-and-variables>`_
    when configuring the bootstrap compiler build:
 
-  * ``-DLLVM_ENABLE_LTO=Thin``
+  * ``-DLLVM_ENABLE_LTO=thin``
   * ``-DCMAKE_C_COMPILER=/path/to/host/clang``
   * ``-DCMAKE_CXX_COMPILER=/path/to/host/clang++``
   * ``-DCMAKE_RANLIB=/path/to/host/llvm-ranlib``
@@ -221,7 +221,7 @@
 
   Or, on Windows:
 
-  * ``-DLLVM_ENABLE_LTO=Thin``
+  * ``-DLLVM_ENABLE_LTO=thin``
   * ``-DCMAKE_C_COMPILER=/path/to/host/clang-cl.exe``
   * ``-DCMAKE_CXX_COMPILER=/path/to/host/clang-cl.exe``
   * ``-DCMAKE_LINKER=/path/to/host/lld-link.exe``