diff --git a/arch/x86/lib/Makefile b/arch/x86/lib/Makefile
index 76f60f5..84aa288 100644
--- a/arch/x86/lib/Makefile
+++ b/arch/x86/lib/Makefile
@@ -5,6 +5,7 @@
 obj-$(CONFIG_SMP) := msr-on-cpu.o
 
 lib-y := delay_$(BITS).o
+lib-y += thunk_$(BITS).o
 lib-y += usercopy_$(BITS).o getuser_$(BITS).o putuser_$(BITS).o
 lib-y += memcpy_$(BITS).o