diff --git a/flang/README.md b/flang/README.md
--- a/flang/README.md
+++ b/flang/README.md
@@ -331,10 +331,14 @@
 # How to Generate Documentation
 
 ## Generate FIR Documentation
-If flang was built with `-DLINK_WITH_FIR=ON` (`ON` by default), it is possible to
-generate FIR language documentation by running `ninja flang-doc`. This will
+It is possible to 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
+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.