diff --git a/Doc/library/sys.rst b/Doc/library/sys.rst
index a0621d4b0dbd09..8a34aabb9267d6 100644
--- a/Doc/library/sys.rst
+++ b/Doc/library/sys.rst
@@ -1039,6 +1039,16 @@ always available. Unless explicitly noted otherwise, all variables are read-only
 
    Get the profiler function as set by :func:`setprofile`.
 
+   .. impl-detail::
+
+      The :func:`getprofile` function is intended only for implementing profilers
+      and similar tools.  When a C profile function is in effect (for example,
+      one installed by ``cProfile``), the returned object is the internal
+      profiler object and not a callable suitable for passing to :func:`setprofile`.
+      As a result, saving and restoring the profiler state using
+      :func:`getprofile` and :func:`setprofile` may not work as expected when
+      C-based profilers are in use.
+
 
 .. function:: gettrace()