diff --git a/unittests/CMakeLists.txt b/unittests/CMakeLists.txt
index 78009a86df5..11a5a5ac975 100644
--- a/unittests/CMakeLists.txt
+++ b/unittests/CMakeLists.txt
@@ -15,6 +15,12 @@ function(add_llvm_unittest test_dirname)
   set_target_properties(${test_name}Tests PROPERTIES FOLDER "Tests")
 endfunction()
 
+# Visual Studio 2012 only supports up to 8 template parameters in
+# std::tr1::tuple by default, but gtest requires 10
+if(MSVC AND MSVC_VERSION EQUAL 1700)
+  add_definitions(-D_VARIADIC_MAX=10)
+endif ()
+
 add_custom_target(UnitTests)
 set_target_properties(UnitTests PROPERTIES FOLDER "Tests")
 
diff --git a/utils/unittest/CMakeLists.txt b/utils/unittest/CMakeLists.txt
index 73491f0721d..70ed35df2e6 100644
--- a/utils/unittest/CMakeLists.txt
+++ b/utils/unittest/CMakeLists.txt
@@ -27,6 +27,12 @@ endif()
 set(LLVM_REQUIRES_RTTI 1)
 add_definitions( -DGTEST_HAS_RTTI=0 )
 
+# Visual Studio 2012 only supports up to 8 template parameters in
+# std::tr1::tuple by default, but gtest requires 10
+if(MSVC AND MSVC_VERSION EQUAL 1700)
+  add_definitions(-D_VARIADIC_MAX=10)
+endif ()
+
 add_llvm_library(gtest
   googletest/gtest.cc
   googletest/gtest-death-test.cc