diff --git a/test/CodeGen/X86/atomic32.ll b/test/CodeGen/X86/atomic32.ll
index 3cb9ca1c76c..3ea96bf1699 100644
--- a/test/CodeGen/X86/atomic32.ll
+++ b/test/CodeGen/X86/atomic32.ll
@@ -2,6 +2,8 @@
 ; RUN: llc < %s -O0 -march=x86 -mcpu=corei7 -verify-machineinstrs | FileCheck %s --check-prefix X32
 ; RUN: llc < %s -O0 -march=x86 -mcpu=corei7 -mattr=-cmov -verify-machineinstrs | FileCheck %s --check-prefix NOCMOV
 
+; XFAIL: cygwin,mingw32,win32
+
 @sc32 = external global i32
 
 define void @atomic_fetch_add32() nounwind {
diff --git a/test/CodeGen/X86/atomic64.ll b/test/CodeGen/X86/atomic64.ll
index aa000455753..d362c31e6db 100644
--- a/test/CodeGen/X86/atomic64.ll
+++ b/test/CodeGen/X86/atomic64.ll
@@ -1,5 +1,7 @@
 ; RUN: llc < %s -O0 -march=x86-64 -mcpu=corei7 -verify-machineinstrs | FileCheck %s --check-prefix X64
 
+; XFAIL: cygwin,mingw32,win32
+
 @sc64 = external global i64
 
 define void @atomic_fetch_add64() nounwind {