diff --git a/modules/libcom/src/osi/os/posix/osdThread.c b/modules/libcom/src/osi/os/posix/osdThread.c
index da17d9b43a..da0342813e 100644
--- a/modules/libcom/src/osi/os/posix/osdThread.c
+++ b/modules/libcom/src/osi/os/posix/osdThread.c
@@ -758,6 +758,9 @@ LIBCOM_API void epicsStdCall epicsThreadSetPriority(epicsThreadId pthreadInfo,un
     assert(epicsThreadOnceCalled);
     assert(pthreadInfo);
     if(!pthreadInfo->isEpicsThread) {
+        /* not allowed to avoid dealing with (potentially) different scheduling
+         * policies (FIFO vs. RR vs. OTHER vs. ...)
+         */
         fprintf(stderr,"epicsThreadSetPriority called by non epics thread\n");
         return;
     }
diff --git a/modules/libcom/test/ringPointerTest.c b/modules/libcom/test/ringPointerTest.c
index 45bb1c68f1..987a881fd9 100644
--- a/modules/libcom/test/ringPointerTest.c
+++ b/modules/libcom/test/ringPointerTest.c
@@ -240,17 +240,32 @@ static void testPair(int locked)
     epicsRingPointerDelete(ring);
 }
 
+static
+void testInThread(void *raw)
+{
+    epicsEventId stop = raw;
+    testPair(0);
+    testPair(1);
+    epicsEventMustTrigger(stop);
+}
+
 MAIN(ringPointerTest)
 {
-    int prio = epicsThreadGetPrioritySelf();
+    epicsThreadId tid;
+    epicsThreadOpts opts = EPICS_THREAD_OPTS_INIT;
+    epicsEventId stop = epicsEventMustCreate(epicsEventEmpty);
 
     testPlan(42);
     testSingle();
-    if (prio)
-        epicsThreadSetPriority(epicsThreadGetIdSelf(), epicsThreadPriorityScanLow);
-    testPair(0);
-    testPair(1);
-    if (prio)
-        epicsThreadSetPriority(epicsThreadGetIdSelf(), prio);
+    /* testPair() needs to run with a priority > 0.
+     * Start a new thread since main() is a "non-epics"
+     * thread, for which we can/should not change the priority
+     */
+    opts.joinable = 1;
+    opts.priority = epicsThreadPriorityScanLow;
+    tid = epicsThreadCreateOpt("RING", testInThread, stop, &opts);
+    epicsEventMustWait(stop);
+    epicsThreadMustJoin(tid);
+    epicsEventDestroy(stop);
     return testDone();
 }