diff --git a/doc/manual/core_language_reference.rst b/doc/manual/core_language_reference.rst
index 9f0a21d06..f4efa4335 100644
--- a/doc/manual/core_language_reference.rst
+++ b/doc/manual/core_language_reference.rst
@@ -18,5 +18,5 @@ The most commonly used features from those modules can be imported with ``from a
 :mod:`artiq.language.units` module
 ----------------------------------
 
-.. automodule:: artiq.language.units
-    :members:
+This module contains floating point constants that correspond to common physical units (ns, MHz, ...).
+They are provided for convenience (e.g write ``MHz`` instead of ``1000000.0``) and code clarity purposes.