diff --git a/lib/sqlalchemy/dialects/mssql/pyodbc.py b/lib/sqlalchemy/dialects/mssql/pyodbc.py
index 42715733de..602e875cbf 100644
--- a/lib/sqlalchemy/dialects/mssql/pyodbc.py
+++ b/lib/sqlalchemy/dialects/mssql/pyodbc.py
@@ -53,6 +53,8 @@ name must be URL encoded which means using plus signs for spaces::
 Other keywords interpreted by the Pyodbc dialect to be passed to
 ``pyodbc.connect()`` in both the DSN and hostname cases include:
 ``odbc_autotranslate``, ``ansi``, ``unicode_results``, ``autocommit``.
+Note that in order for the dialect to recognize these keywords
+(including the ``driver`` keyword above) they must be all lowercase.
 
 Pass through exact Pyodbc string
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^