diff --git a/configure.ac b/configure.ac
index 322bfda0e5..943a639884 100644
--- a/configure.ac
+++ b/configure.ac
@@ -62,7 +62,7 @@ AM_PROG_CC_C_O
 AC_GNU_SOURCE
 AC_PROG_INTLTOOL
 # Ensure the compiler supports C++ 11:
-AX_CXX_COMPILE_STDCXX_11(noext)
+AX_CXX_COMPILE_STDCXX_11(ext)
 
 
 AC_SUBST(GNUCASH_MAJOR_VERSION)