diff --git a/.ci/travis-build.sh b/.ci/travis-build.sh
index c71bdd90e..bf6d605d1 100755
--- a/.ci/travis-build.sh
+++ b/.ci/travis-build.sh
@@ -72,6 +72,7 @@ make -j2 RTEMS_QEMU_FIXUPS=YES CMD_CFLAGS="${CMD_CFLAGS}" CMD_CXXFLAGS="${CMD_CX
 
 if [ "$TEST" != "NO" ]
 then
+   export EPICS_TEST_IMPRECISE_TIMING=YES
    make -j2 tapfiles
    make -s test-results
 fi
diff --git a/modules/libcom/src/misc/epicsUnitTest.c b/modules/libcom/src/misc/epicsUnitTest.c
index dce05983e..22fbc1f2a 100644
--- a/modules/libcom/src/misc/epicsUnitTest.c
+++ b/modules/libcom/src/misc/epicsUnitTest.c
@@ -15,6 +15,7 @@
 
 #include <stdio.h>
 #include <stdlib.h>
+#include <string.h>
 
 #ifdef _WIN32
 #  include <crtdbg.h>
@@ -248,6 +249,17 @@ int testDone(void) {
     return (status);
 }
 
+static int impreciseTiming;
+
+int testImpreciseTiming(void)
+{
+    if(impreciseTiming==0) {
+        const char* env = getenv("EPICS_TEST_IMPRECISE_TIMING");
+
+        impreciseTiming = (env && strcmp(env, "YES")==0) ? 1 : -1;
+    }
+    return impreciseTiming>0;
+}
 
 /* Our test harness, for RTEMS and vxWorks */
 
diff --git a/modules/libcom/src/misc/epicsUnitTest.h b/modules/libcom/src/misc/epicsUnitTest.h
index 9a119ad22..b0199333e 100644
--- a/modules/libcom/src/misc/epicsUnitTest.h
+++ b/modules/libcom/src/misc/epicsUnitTest.h
@@ -40,6 +40,8 @@ epicsShareFunc int  testDone(void);
 
 #define testOk1(cond) testOk(cond, "%s", #cond)
 
+epicsShareFunc
+int testImpreciseTiming(void);
 
 typedef int (*TESTFUNC)(void);
 epicsShareFunc void testHarness(void);
diff --git a/modules/libcom/test/epicsTimerTest.cpp b/modules/libcom/test/epicsTimerTest.cpp
index 12e5eaeb2..e3b36a8c1 100644
--- a/modules/libcom/test/epicsTimerTest.cpp
+++ b/modules/libcom/test/epicsTimerTest.cpp
@@ -112,9 +112,13 @@ double delayVerify::checkError () const
     double actualDelay =  this->expireStamp - this->beginStamp;
     double measuredError = actualDelay - this->expectedDelay;
     double percentError = 100.0 * fabs ( measuredError ) / this->expectedDelay;
+    if(testImpreciseTiming())
+        testTodoBegin("imprecise");
     testOk ( percentError < messageThresh, "%f < %f, delay = %f s, error = %f s (%.1f %%)",
              percentError, messageThresh,
              this->expectedDelay, measuredError, percentError  );
+    if(testImpreciseTiming())
+        testTodoEnd();
     return measuredError;
 }