diff --git a/modules/libcom/test/epicsEventTest.cpp b/modules/libcom/test/epicsEventTest.cpp
index c58e57c11..9a6e48a8f 100644
--- a/modules/libcom/test/epicsEventTest.cpp
+++ b/modules/libcom/test/epicsEventTest.cpp
@@ -171,6 +171,10 @@ static double eventWaitCheckDelayError( const epicsEventId &id, const double & d
 #define WAITCOUNT 21
 static void eventWaitTest()
 {
+#if defined(_WIN32) || defined(__rtems__) || defined(vxWorks)
+    testTodoBegin("Known issue with delay calculation");
+#endif
+
     epicsEventId event = epicsEventMustCreate(epicsEventEmpty);
     double errorSum = eventWaitCheckDelayError(event, 0.0);
 
@@ -181,6 +185,8 @@ static void eventWaitTest()
     double meanError = errorSum / WAITCOUNT;
     testOk(meanError < 0.05, "Mean delay error was %.6f sec", meanError);
 
+    testTodoEnd();
+
     epicsEventDestroy(event);
 }