--- Tests/UnitTests/V2LibraryTests/FunctionTests.cpp.old	2017-07-07 13:03:11.977578491 +0200
+++ Tests/UnitTests/V2LibraryTests/FunctionTests.cpp	2017-07-07 13:03:26.434040010 +0200
@@ -1040,7 +1040,7 @@
     for (auto dropoutRate : { 0.9, 0.4, 0.0, 0.1 }) 
     {
         dropout->SetAttribute(L"dropoutRate", dropoutRate);
-        BOOST_TEST(abs(zeroCount(forwardFunc(dropout)) - dropoutRate*shape.TotalSize()) < 100);
+        BOOST_TEST(fabs(zeroCount(forwardFunc(dropout)) - dropoutRate*shape.TotalSize()) < 100);
     }
 
     auto plusParam = CNTK::Parameter(CNTK::NDArrayView::RandomUniform<float>(shape, -0.5, 0.5, 1, device));
@@ -1051,7 +1051,7 @@
     for (auto dropoutRate : { 0.3, 0.7, 0.2 })
     {
         dropout2->SetAttribute(L"dropoutRate", dropoutRate);
-        BOOST_TEST(abs(zeroCount(forwardFunc(combine)) - dropoutRate*shape.TotalSize()) < 100);
+        BOOST_TEST(fabs(zeroCount(forwardFunc(combine)) - dropoutRate*shape.TotalSize()) < 100);
     }
 }
 
