diff --git a/config/gthr.m4 b/config/gthr.m4
index 4b937306ad0..11996247f15 100644
--- a/config/gthr.m4
+++ b/config/gthr.m4
@@ -22,6 +22,7 @@ case $1 in
     tpf)	thread_header=config/s390/gthr-tpf.h ;;
     vxworks)	thread_header=config/gthr-vxworks.h ;;
     win32)	thread_header=config/i386/gthr-win32.h ;;
+    mcf)	thread_header=config/i386/gthr-mcf.h ;;
 esac
 AC_SUBST(thread_header)
 ])