diff --git a/configure.ac b/configure.ac
index b3e98a6..0c83ce0 100644
--- a/configure.ac
+++ b/configure.ac
@@ -698,7 +698,7 @@ AC_CACHE_CHECK([stdatomic.h atomic primitives], fc_cv_have_stdatomic_atomic_prim
 	)
 ])
 if $fc_cv_have_stdatomic_atomic_primitives; then
-	AC_DEFINE(HAVE_STDATOMIC_PRIMITIVES, 1, [Have Intel __sync_* atomic primitives])
+	AC_DEFINE(HAVE_STDATOMIC_PRIMITIVES, 1, [Have C99 stdatomic atomic primitives])
 fi
 
 AC_CACHE_CHECK([for Intel atomic primitives], fc_cv_have_intel_atomic_primitives, [