diff --git a/package/cups-filters/cups-filters.mk b/package/cups-filters/cups-filters.mk
index eaad301c6d..2c682b92f3 100644
--- a/package/cups-filters/cups-filters.mk
+++ b/package/cups-filters/cups-filters.mk
@@ -12,6 +12,7 @@ CUPS_FILTERS_CPE_ID_VENDOR = linuxfoundation
 
 # 0003-libcupsfilters-Fixed-building-with-QPDF-11.x.patch
 # 0004-Updated-code-to-be-built-with-QPDF-12.x.patch
+# ax_cxx_compile_stdcxx.m4 needs to be updated for gcc 16.x (C++20)
 CUPS_FILTERS_AUTORECONF = YES
 
 # 0001-beh-backend-Use-execv-instead-of-system-CVE-2023-24805.patch