diff --git a/acinclude.m4 b/acinclude.m4
index cc45cf371..37b7efdaa 100644
--- a/acinclude.m4
+++ b/acinclude.m4
@@ -487,7 +487,7 @@ AC_DEFUN([GB_SYSTEM],
       AC_DEFINE(ARCH_X86, 1, [Target architecture is x86])
       AC_DEFINE(ARCHITECTURE, "x86", [Architecture])
       ;;
-    x86_64-*-*-* | amd64-* | ia64-* )
+    x86_64-*-* | amd64-* | ia64-* )
       ARCH=X86_64
       AC_DEFINE(ARCH_X86_64, 1, [Target architecture is x86_64])
       AC_DEFINE(ARCHITECTURE, "x86_64", [Architecture])