diff --git a/docs/source/configure.rst b/docs/source/configure.rst
index 9ed1a484..a3fbb635 100644
--- a/docs/source/configure.rst
+++ b/docs/source/configure.rst
@@ -51,10 +51,11 @@ isn't mentioned in the list of :ref:`settings <settings>`.
 Configuration File
 ==================
 
-The configuration file should be a valid Python source file. It only needs to
-be readable from the file system. More specifically, it does not need to be
-importable. Any Python is valid. Just consider that this will be run every time
-you start Gunicorn (including when you signal Gunicorn to reload).
+The configuration file should be a valid Python source file with a **python
+extension** (e.g. `gunicorn.conf.py`). It only needs to be readable from the
+file system. More specifically, it does not need to be importable. Any Python
+is valid. Just consider that this will be run every time you start Gunicorn
+(including when you signal Gunicorn to reload).
 
 To set a parameter, just assign to it. There's no special syntax. The values
 you provide will be used for the configuration values.