diff --git a/src/libthread/mkfile b/src/libthread/mkfile
index d552d07..07569a6 100644
--- a/src/libthread/mkfile
+++ b/src/libthread/mkfile
@@ -36,6 +36,9 @@
 OpenBSD-%-asm.$O:	OpenBSD-%-asm.S
 	$CC $CFLAGS OpenBSD-$stem-asm.S
 
+Linux-sparc64-context.$O: Linux-sparc64-context.S
+	$CC $CFLAGS Linux-sparc64-context.S
+
 test:V: tprimes tspawn
 	primes 1 10007 >p1.txt
 	$PLAN9/bin/time ./tprimes 10000 >tp1.txt
@@ -48,3 +51,4 @@
 
 CLEANFILES=p1.txt p2.txt tp1.txt tp2.txt
 
+