diff --git a/arch/x86/include/asm/system.h b/arch/x86/include/asm/system.h
index 8e626ea..fa47b1e 100644
--- a/arch/x86/include/asm/system.h
+++ b/arch/x86/include/asm/system.h
@@ -96,15 +96,15 @@
 	     "thread_return:\n\t"					  \
 	     "movq %%gs:%P[pda_pcurrent],%%rsi\n\t"			  \
 	     "movq %P[thread_info](%%rsi),%%r8\n\t"			  \
-	     LOCK_PREFIX "btr  %[tif_fork],%P[ti_flags](%%r8)\n\t"	  \
 	     "movq %%rax,%%rdi\n\t" 					  \
-	     "jc   ret_from_fork\n\t"					  \
+	     "testl  %[_tif_fork],%P[ti_flags](%%r8)\n\t"	  \
+	     "jnz   ret_from_fork\n\t"					  \
 	     RESTORE_CONTEXT						  \
 	     : "=a" (last)					  	  \
 	     : [next] "S" (next), [prev] "D" (prev),			  \
 	       [threadrsp] "i" (offsetof(struct task_struct, thread.sp)), \
 	       [ti_flags] "i" (offsetof(struct thread_info, flags)),	  \
-	       [tif_fork] "i" (TIF_FORK),			  	  \
+	       [_tif_fork] "i" (_TIF_FORK),			  	  \
 	       [thread_info] "i" (offsetof(struct task_struct, stack)),   \
 	       [pda_pcurrent] "i" (offsetof(struct x8664_pda, pcurrent))  \
 	     : "memory", "cc" __EXTRA_CLOBBER)