diff --git a/flang/README.md b/flang/README.md
--- a/flang/README.md
+++ b/flang/README.md
@@ -335,6 +335,12 @@
 generate FIR language documentation by running `ninja flang-doc`. This will
 create `<build-dir>/tools/flang/docs/Dialect/FIRLangRef.md` in flang build directory.
 
+```bash
+cd ~/llvm-project/build
+cmake -DLINK_WITH_FIR=ON ../llvm
+ninja flang-doc
+```
+
 ## Generate Doxygen-based Documentation
 To generate doxygen-style documentation from source code
 - Pass `-DLLVM_ENABLE_DOXYGEN=ON -DFLANG_INCLUDE_DOCS=ON` to the cmake command.