diff --git a/doc/src/extensions.rst b/doc/src/extensions.rst
index 3f010665..84e12412 100644
--- a/doc/src/extensions.rst
+++ b/doc/src/extensions.rst
@@ -199,12 +199,14 @@ functionalities defined by the |DBAPI|_.
 
 .. function:: libpq_version()
 
-    Query actual ``libpq`` version loaded.
+    Return the version number of the ``libpq`` dynamic library loaded as an
+    integer, in the same format of `~connection.server_version`.
 
-    This function throws `NotSupportedError` if it was compiled with
-    ``libpq < 9.1``.
+    Raise `~psycopg2.NotSupportedError` if the ``psycopg2`` module was
+    compiled with a ``libpq`` version lesser than 9.1 (which can be detected
+    by the `~psycopg2.__libpq_version__` constant).
 
-    .. seealso:: libpq docs for `PQlibVersion()`__
+    .. seealso:: libpq docs for `PQlibVersion()`__.
 
         .. __: http://www.postgresql.org/docs/current/static/libpq-misc.html#LIBPQ-PQLIBVERSION
 
diff --git a/doc/src/module.rst b/doc/src/module.rst
index bd6bcf45..bd121e9d 100644
--- a/doc/src/module.rst
+++ b/doc/src/module.rst
@@ -111,10 +111,11 @@ The module interface respects the standard defined in the |DBAPI|_.
 
 .. data:: __libpq_version__
 
-   Integer contant containing the version of ``libpq`` this `psycopg2`
-   module was compiled with.  If this value is ``>= 90100`` then you
-   may query for the actually loaded version of libpq using
-   `~psycopg2.extensions.libpq_version()`.
+   Integer constant reporting the version of the ``libpq`` library this
+   ``psycopg2`` module was compiled with (in the same format of
+   `~connection.server_version`).  If this value is lesser than ``90100``
+   then you may query the version of the actually loaded library using the
+   `~psycopg2.extensions.libpq_version()` function.
 
 
 .. index::