diff --git a/llvm/docs/WritingAnLLVMPass.rst b/llvm/docs/WritingAnLLVMPass.rst
--- a/llvm/docs/WritingAnLLVMPass.rst
+++ b/llvm/docs/WritingAnLLVMPass.rst
@@ -474,7 +474,8 @@
 To be explicit, ``FunctionPass`` subclasses are not allowed to:
 
 #. Inspect or modify a ``Function`` other than the one currently being processed.
-#. Add or remove ``Function``\ s from the current ``Module``.
+#. Add or remove ``Function``\ s from the current ``Module``, including
+   declarations.
 #. Add or remove global variables from the current ``Module``.
 #. Maintain state across invocations of :ref:`runOnFunction
    <writing-an-llvm-pass-runOnFunction>` (including global data).