diff --git a/configure.in b/configure.in
index 7eaefb92..bd9ad7fc 100644
--- a/configure.in
+++ b/configure.in
@@ -19,6 +19,7 @@ ifdef([AC_USE_SYSTEM_EXTENSIONS], [
 AC_USE_SYSTEM_EXTENSIONS
 ], [
 AC_AIX
+AC_GNU_SOURCE
 AC_MINIX
 ])