diff --git a/configure.ac b/configure.ac
index 0f78714..edaf450 100644
--- a/configure.ac
+++ b/configure.ac
@@ -18,7 +18,7 @@
 
 LT_INIT
 
-AX_CXX_COMPILE_STDCXX_17([noext])
+AX_CXX_COMPILE_STDCXX([20], [noext])
 AX_APPEND_COMPILE_FLAGS([-Wall -Werror], [CXXFLAGS])
 
 AC_ARG_VAR(SETTINGS_BUSNAME, [The Dbus busname to own])