diff --git a/CMakeLists.txt b/CMakeLists.txt
index a99ca38b1..c5c9a24f4 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -57,7 +57,9 @@ option(ENABLE_PROGRAMS "Build mbed TLS programs." ON)
 option(UNSAFE_BUILD "Allow unsafe builds. These builds ARE NOT SECURE." OFF)
 option(MBEDTLS_FATAL_WARNINGS "Compiler warnings treated as errors" ON)
 if(CMAKE_HOST_WIN32)
-    # N.B. The comment on the next line is significant for prepare_release.sh
+    # N.B. The comment on the next line is significant! If you change it,
+    # edit the sed command in prepare_release.sh that modifies
+    # CMakeLists.txt.
     option(GEN_FILES "Generate the auto-generated files as needed" OFF) # off in development
 else()
     option(GEN_FILES "Generate the auto-generated files as needed" ON)