diff --git a/Include/patchlevel.h b/Include/patchlevel.h
index 33f922c..aa0d6fc 100644
--- a/Include/patchlevel.h
+++ b/Include/patchlevel.h
@@ -6,7 +6,7 @@
    defined(PY_MAJOR_VERSION).
 
    When the major or minor version changes, the VERSION variable in
-   configure.in must also be changed.
+   configure.ac must also be changed.
 
    There is also (independent) API version information in modsupport.h.
 */