diff --git a/Misc/python.man b/Misc/python.man
index a191cab..3cdf884 100644
--- a/Misc/python.man
+++ b/Misc/python.man
@@ -495,6 +495,9 @@
 If this environment variable is set to a non-empty string, Python will
 show how long each import takes. This is exactly equivalent to setting
 \fB\-X importtime\fP on the command line.
+.IP PYTHONBREAKPOINT
+If this environment variable is set to 0, it disables the default debugger. It
+can be set to the callable of your debugger of choice.
 .SS Debug-mode variables
 Setting these variables only has an effect in a debug build of Python, that is,
 if Python was configured with the
diff --git a/Modules/main.c b/Modules/main.c
index 3a6cf31..8000a1a 100644
--- a/Modules/main.c
+++ b/Modules/main.c
@@ -144,6 +144,8 @@
 "PYTHONCOERCECLOCALE: if this variable is set to 0, it disables the locale\n"
 "   coercion behavior. Use PYTHONCOERCECLOCALE=warn to request display of\n"
 "   locale coercion and locale compatibility warnings on stderr.\n"
+"PYTHONBREAKPOINT: if this variable is set to 0, it disables the default\n"
+"   debugger. It can be set to the callable of your debugger of choice.\n"
 "PYTHONDEVMODE: enable the development mode.\n"
 "PYTHONPYCACHEPREFIX: root directory for bytecode cache (pyc) files.\n";