diff --git a/docs/environment.rst b/docs/environment.rst
index 442c340f1a4d4..b97820b3caf74 100644
--- a/docs/environment.rst
+++ b/docs/environment.rst
@@ -53,8 +53,10 @@ Details of the toml language subset
 CircuitPython behavior
 ----------------------
 
-CircuitPython will also read the environment to configure its behavior. Other
-keys are ignored by CircuitPython. Here are the keys it uses:
+CircuitPython will also read the environment to configure its behavior. Some keys are read at
+startup once and others are read on reload (ctrl-D in the REPL). If a reload doesn't change things,
+then try a reset (a power cycle or pressing the reset button). Other keys are ignored by CircuitPython.
+Here are the keys it uses:
 
 Core CircuitPython keys
 ^^^^^^^^^^^^^^^^^^^^^^^