diff --git a/pjlib/src/pjlib-test/test.c b/pjlib/src/pjlib-test/test.c
index 055f8a2c9b..6ccb712238 100644
--- a/pjlib/src/pjlib-test/test.c
+++ b/pjlib/src/pjlib-test/test.c
@@ -254,8 +254,17 @@ static int features_tests(int argc, char *argv[])
     UT_ADD_TEST(&test_app.ut_app, timer_test, 0);
 #endif
 
+    /* Very often sleep test failed on GitHub Windows CI, with
+       the thread sleeping for much longer than tolerated. So
+       as a workaround, set it as exclusive.
+     */
 #if INCLUDE_SLEEP_TEST
+#  if defined(PJ_WIN32) && PJ_WIN32!=0
+    UT_ADD_TEST(&test_app.ut_app, sleep_test,
+                PJ_TEST_EXCLUSIVE | PJ_TEST_KEEP_LAST);
+#  else
     UT_ADD_TEST(&test_app.ut_app, sleep_test, 0);
+#  endif
 #endif
 
 #if INCLUDE_FILE_TEST
@@ -299,7 +308,8 @@ static int features_tests(int argc, char *argv[])
     */
 #if INCLUDE_IOQUEUE_STRESS_TEST
 #  if defined(PJ_WIN32) && PJ_WIN32!=0
-    UT_ADD_TEST(&test_app.ut_app, ioqueue_stress_test, PJ_TEST_EXCLUSIVE);
+    UT_ADD_TEST(&test_app.ut_app, ioqueue_stress_test,
+                PJ_TEST_EXCLUSIVE | PJ_TEST_KEEP_LAST);
 #  else
     UT_ADD_TEST(&test_app.ut_app, ioqueue_stress_test, 0);
 #  endif