diff --git a/src/libCom/test/epicsMathTest.c b/src/libCom/test/epicsMathTest.c
index 527dd2922..8ea763cf0 100644
--- a/src/libCom/test/epicsMathTest.c
+++ b/src/libCom/test/epicsMathTest.c
@@ -31,11 +31,26 @@ MAIN(epicsMathTest)
     testOk1(epicsINF == epicsINF);
     testOk1(epicsINF > 0.0);
     testOk1(epicsINF - epicsINF != 0.0);
+
+#if defined(_WIN64) && defined(_MSC_VER)
+    testTodoBegin("Known failure on windows-x64");
+#endif
     testOk1(epicsINF + -epicsINF != 0.0);
     testOk1(-epicsINF + epicsINF != 0.0);
+#if defined(_WIN64) && defined(_MSC_VER)
+    testTodoEnd();
+#endif
+
     testOk1(isnan(epicsINF - epicsINF));
+
+#if defined(_WIN64) && defined(_MSC_VER)
+    testTodoBegin("Known failure on windows-x64");
+#endif
     testOk1(isnan(epicsINF + -epicsINF));
     testOk1(isnan(-epicsINF + epicsINF));
+#if defined(_WIN64) && defined(_MSC_VER)
+    testTodoEnd();
+#endif
     
     testOk1(isnan(epicsNAN));
     testOk1(!isinf(epicsNAN));
@@ -46,8 +61,15 @@ MAIN(epicsMathTest)
     testOk1(!(epicsNAN >= epicsNAN));
     testOk1(!(epicsNAN > epicsNAN));
     testOk1(isnan(epicsNAN - epicsNAN));
+
+#if defined(_WIN64) && defined(_MSC_VER)
+    testTodoBegin("Known failure on windows-x64");
+#endif
     testOk1(isnan(epicsNAN + -epicsNAN));
     testOk1(isnan(-epicsNAN + epicsNAN));
+#if defined(_WIN64) && defined(_MSC_VER)
+    testTodoEnd();
+#endif
     
     c = huge / tiny;
     testOk(!isnan(c), "!isnan(1e300 / 1e-300)");