diff --git libgomp/plugin/plugin-nvptx.c libgomp/plugin/plugin-nvptx.c
index 7d0d38e0c2e1..6f9b16634b10 100644
--- libgomp/plugin/plugin-nvptx.c
+++ libgomp/plugin/plugin-nvptx.c
@@ -1539,9 +1539,8 @@ nvptx_async_test (int async)
   struct ptx_stream *s;
 
   s = select_stream_for_async (async, pthread_self (), false, NULL);
-
   if (!s)
-    GOMP_PLUGIN_fatal ("unknown async %d", async);
+    return 1;
 
   r = CUDA_CALL_NOCHECK (cuStreamQuery, s->stream);
   if (r == CUDA_SUCCESS)
@@ -1596,7 +1595,7 @@ nvptx_wait (int async)
 
   s = select_stream_for_async (async, pthread_self (), false, NULL);
   if (!s)
-    GOMP_PLUGIN_fatal ("unknown async %d", async);
+    return;
 
   CUDA_CALL_ASSERT (cuStreamSynchronize, s->stream);
 
@@ -1610,14 +1609,14 @@ nvptx_wait_async (int async1, int async2)
   struct ptx_stream *s1, *s2;
   pthread_t self = pthread_self ();
 
+  s1 = select_stream_for_async (async1, self, false, NULL);
+  if (!s1)
+    return;
+
   /* The stream that is waiting (rather than being waited for) doesn't
      necessarily have to exist already.  */
   s2 = select_stream_for_async (async2, self, true, NULL);
 
-  s1 = select_stream_for_async (async1, self, false, NULL);
-  if (!s1)
-    GOMP_PLUGIN_fatal ("invalid async 1\n");
-
   if (s1 == s2)
     GOMP_PLUGIN_fatal ("identical parameters");
 
diff --git libgomp/testsuite/libgomp.oacc-c-c++-common/async_queue-1.c libgomp/testsuite/libgomp.oacc-c-c++-common/async_queue-1.c
index 48e1846a36e3..544b19fe6635 100644
--- libgomp/testsuite/libgomp.oacc-c-c++-common/async_queue-1.c
+++ libgomp/testsuite/libgomp.oacc-c-c++-common/async_queue-1.c
@@ -41,6 +41,36 @@ int main(void)
       assert (queues[i].cuda_stream == NULL);
     }
 
+  /* No-ops still don't initialize them.  */
+  {
+    size_t i = 0;
+    /* Find the first non-special async-argument.  */
+    while (queues[i].async < 0)
+      ++i;
+    assert (i < queues_n);
+
+#pragma acc wait(queues[i].async) // no-op
+
+    ++i;
+    assert (i < queues_n);
+#pragma acc parallel wait(queues[i].async) // no-op
+    ;
+
+    ++i;
+    assert (i < queues_n);
+    acc_wait(queues[i].async); // no-op
+
+    i += 2;
+    assert (i < queues_n);
+    acc_wait_async(queues[i - 1].async, queues[i].async); // no-op, and async queue "i" does not get set up
+
+    for (size_t i = 0; i < queues_n; ++i)
+      {
+	queues[i].cuda_stream = acc_get_cuda_stream (queues[i].async);
+	assert (queues[i].cuda_stream == NULL);
+      }
+  }
+
   for (size_t i = 0; i < queues_n; ++i)
     {
       /* Use the queue to initialize it.  */
diff --git libgomp/testsuite/libgomp.oacc-c-c++-common/data-2-lib.c libgomp/testsuite/libgomp.oacc-c-c++-common/data-2-lib.c
index 2ddfa7d4a01b..806c2f405a01 100644
--- libgomp/testsuite/libgomp.oacc-c-c++-common/data-2-lib.c
+++ libgomp/testsuite/libgomp.oacc-c-c++-common/data-2-lib.c
@@ -65,6 +65,8 @@ main (int argc, char **argv)
     b[i] = a[i];
 
   acc_wait (1);
+  /* Test unseen async-argument.  */
+  acc_wait (10);
 
   acc_memcpy_from_device (a, d_a, nbytes);
   acc_memcpy_from_device (b, d_b, nbytes);
diff --git libgomp/testsuite/libgomp.oacc-c-c++-common/data-2.c libgomp/testsuite/libgomp.oacc-c-c++-common/data-2.c
index 0c6abe69dc17..b552b94529d8 100644
--- libgomp/testsuite/libgomp.oacc-c-c++-common/data-2.c
+++ libgomp/testsuite/libgomp.oacc-c-c++-common/data-2.c
@@ -85,6 +85,8 @@ main (int argc, char **argv)
 
 #pragma acc exit data copyout (a[0:N]) copyout (b[0:N]) wait (1) async (1)
 #pragma acc wait (1)
+  /* Test unseen async-argument.  */
+#pragma acc wait (10)
 
   for (i = 0; i < N; i++)
     {
diff --git libgomp/testsuite/libgomp.oacc-c-c++-common/lib-69.c libgomp/testsuite/libgomp.oacc-c-c++-common/lib-69.c
index 5462f1253522..c10bebaab136 100644
--- libgomp/testsuite/libgomp.oacc-c-c++-common/lib-69.c
+++ libgomp/testsuite/libgomp.oacc-c-c++-common/lib-69.c
@@ -103,6 +103,13 @@ main (int argc, char **argv)
       abort ();
     }
 
+  /* Test unseen async-argument.  */
+  if (acc_async_test (1) != 1)
+    {
+      fprintf (stderr, "acc_async_test failed on unseen async-argument\n");
+      abort ();
+    }
+
   sleep (1);
 
   if (acc_async_test (0) != 1)
diff --git libgomp/testsuite/libgomp.oacc-c-c++-common/lib-71.c libgomp/testsuite/libgomp.oacc-c-c++-common/lib-71.c
deleted file mode 100644
index c85e82459554..000000000000
--- libgomp/testsuite/libgomp.oacc-c-c++-common/lib-71.c
+++ /dev/null
@@ -1,122 +0,0 @@
-/* { dg-do run { target openacc_nvidia_accel_selected } } */
-/* { dg-additional-options "-lcuda" } */
-
-#include <stdio.h>
-#include <unistd.h>
-#include <openacc.h>
-#include <cuda.h>
-
-int
-main (int argc, char **argv)
-{
-  CUdevice dev;
-  CUfunction delay;
-  CUmodule module;
-  CUresult r;
-  CUstream stream;
-  unsigned long *a, *d_a, dticks;
-  int nbytes;
-  float dtime;
-  void *kargs[2];
-  int clkrate;
-  int devnum, nprocs;
-
-  acc_init (acc_device_nvidia);
-
-  devnum = acc_get_device_num (acc_device_nvidia);
-
-  r = cuDeviceGet (&dev, devnum);
-  if (r != CUDA_SUCCESS)
-    {
-      fprintf (stderr, "cuDeviceGet failed: %d\n", r);
-      abort ();
-    }
-
-  r =
-    cuDeviceGetAttribute (&nprocs, CU_DEVICE_ATTRIBUTE_MULTIPROCESSOR_COUNT,
-			  dev);
-  if (r != CUDA_SUCCESS)
-    {
-      fprintf (stderr, "cuDeviceGetAttribute failed: %d\n", r);
-      abort ();
-    }
-
-  r = cuDeviceGetAttribute (&clkrate, CU_DEVICE_ATTRIBUTE_CLOCK_RATE, dev);
-  if (r != CUDA_SUCCESS)
-    {
-      fprintf (stderr, "cuDeviceGetAttribute failed: %d\n", r);
-      abort ();
-    }
-
-  r = cuModuleLoad (&module, "subr.ptx");
-  if (r != CUDA_SUCCESS)
-    {
-      fprintf (stderr, "cuModuleLoad failed: %d\n", r);
-      abort ();
-    }
-
-  r = cuModuleGetFunction (&delay, module, "delay");
-  if (r != CUDA_SUCCESS)
-    {
-      fprintf (stderr, "cuModuleGetFunction failed: %d\n", r);
-      abort ();
-    }
-
-  nbytes = nprocs * sizeof (unsigned long);
-
-  dtime = 200.0;
-
-  dticks = (unsigned long) (dtime * clkrate);
-
-  a = (unsigned long *) malloc (nbytes);
-  d_a = (unsigned long *) acc_malloc (nbytes);
-
-  acc_map_data (a, d_a, nbytes);
-
-  kargs[0] = (void *) &d_a;
-  kargs[1] = (void *) &dticks;
-
-  r = cuStreamCreate (&stream, CU_STREAM_DEFAULT);
-  if (r != CUDA_SUCCESS)
-	{
-	  fprintf (stderr, "cuStreamCreate failed: %d\n", r);
-	  abort ();
-	}
-
-  acc_set_cuda_stream (0, stream);
-
-  r = cuLaunchKernel (delay, 1, 1, 1, 1, 1, 1, 0, stream, kargs, 0);
-  if (r != CUDA_SUCCESS)
-    {
-      fprintf (stderr, "cuLaunchKernel failed: %d\n", r);
-      abort ();
-    }
-
-  fprintf (stderr, "CheCKpOInT\n");
-  if (acc_async_test (1) != 0)
-    {
-      fprintf (stderr, "asynchronous operation not running\n");
-      abort ();
-    }
-
-  sleep ((int) (dtime / 1000.0f) + 1);
-
-  if (acc_async_test (1) != 1)
-    {
-      fprintf (stderr, "found asynchronous operation still running\n");
-      abort ();
-    }
-
-  acc_unmap_data (a);
-
-  free (a);
-  acc_free (d_a);
-
-  acc_shutdown (acc_device_nvidia);
-
-  return 0;
-}
-
-/* { dg-output "CheCKpOInT(\n|\r\n|\r).*" } */
-/* { dg-output "unknown async \[0-9\]+" } */
-/* { dg-shouldfail "" } */
diff --git libgomp/testsuite/libgomp.oacc-c-c++-common/lib-74.c libgomp/testsuite/libgomp.oacc-c-c++-common/lib-74.c
index 0726ee420c3f..0efcf0d52229 100644
--- libgomp/testsuite/libgomp.oacc-c-c++-common/lib-74.c
+++ libgomp/testsuite/libgomp.oacc-c-c++-common/lib-74.c
@@ -103,6 +103,8 @@ main (int argc, char **argv)
     }
 
   acc_wait (0);
+  /* Test unseen async-argument.  */
+  acc_wait (1);
 
   atime = stop_timer (0);
 
@@ -115,6 +117,8 @@ main (int argc, char **argv)
   start_timer (0);
 
   acc_wait (0);
+  /* Test unseen async-argument.  */
+  acc_wait (1);
 
   atime = stop_timer (0);
 
diff --git libgomp/testsuite/libgomp.oacc-c-c++-common/lib-77.c libgomp/testsuite/libgomp.oacc-c-c++-common/lib-77.c
deleted file mode 100644
index f4f196def3b7..000000000000
--- libgomp/testsuite/libgomp.oacc-c-c++-common/lib-77.c
+++ /dev/null
@@ -1,138 +0,0 @@
-/* { dg-do run { target openacc_nvidia_accel_selected } } */
-/* { dg-additional-options "-lcuda" } */
-
-#include <stdio.h>
-#include <stdlib.h>
-#include <unistd.h>
-#include <openacc.h>
-#include <cuda.h>
-#include "timer.h"
-
-int
-main (int argc, char **argv)
-{
-  CUdevice dev;
-  CUfunction delay;
-  CUmodule module;
-  CUresult r;
-  CUstream stream;
-  unsigned long *a, *d_a, dticks;
-  int nbytes;
-  float atime, dtime;
-  void *kargs[2];
-  int clkrate;
-  int devnum, nprocs;
-
-  acc_init (acc_device_nvidia);
-
-  devnum = acc_get_device_num (acc_device_nvidia);
-
-  r = cuDeviceGet (&dev, devnum);
-  if (r != CUDA_SUCCESS)
-    {
-      fprintf (stderr, "cuDeviceGet failed: %d\n", r);
-      abort ();
-    }
-
-  r =
-    cuDeviceGetAttribute (&nprocs, CU_DEVICE_ATTRIBUTE_MULTIPROCESSOR_COUNT,
-			  dev);
-  if (r != CUDA_SUCCESS)
-    {
-      fprintf (stderr, "cuDeviceGetAttribute failed: %d\n", r);
-      abort ();
-    }
-
-  r = cuDeviceGetAttribute (&clkrate, CU_DEVICE_ATTRIBUTE_CLOCK_RATE, dev);
-  if (r != CUDA_SUCCESS)
-    {
-      fprintf (stderr, "cuDeviceGetAttribute failed: %d\n", r);
-      abort ();
-    }
-
-  r = cuModuleLoad (&module, "subr.ptx");
-  if (r != CUDA_SUCCESS)
-    {
-      fprintf (stderr, "cuModuleLoad failed: %d\n", r);
-      abort ();
-    }
-
-  r = cuModuleGetFunction (&delay, module, "delay");
-  if (r != CUDA_SUCCESS)
-    {
-      fprintf (stderr, "cuModuleGetFunction failed: %d\n", r);
-      abort ();
-    }
-
-  nbytes = nprocs * sizeof (unsigned long);
-
-  dtime = 200.0;
-
-  dticks = (unsigned long) (dtime * clkrate);
-
-  a = (unsigned long *) malloc (nbytes);
-  d_a = (unsigned long *) acc_malloc (nbytes);
-
-  acc_map_data (a, d_a, nbytes);
-
-  kargs[0] = (void *) &d_a;
-  kargs[1] = (void *) &dticks;
-
-  r = cuStreamCreate (&stream, CU_STREAM_DEFAULT);
-  if (r != CUDA_SUCCESS)
-	{
-	  fprintf (stderr, "cuStreamCreate failed: %d\n", r);
-	  abort ();
-	}
-
-  acc_set_cuda_stream (0, stream);
-
-  init_timers (1);
-
-  start_timer (0);
-
-  r = cuLaunchKernel (delay, 1, 1, 1, 1, 1, 1, 0, stream, kargs, 0);
-  if (r != CUDA_SUCCESS)
-    {
-      fprintf (stderr, "cuLaunchKernel failed: %d\n", r);
-      abort ();
-    }
-
-  fprintf (stderr, "CheCKpOInT\n");
-  acc_wait (1);
-
-  atime = stop_timer (0);
-
-  if (atime < dtime)
-    {
-      fprintf (stderr, "actual time < delay time\n");
-      abort ();
-    }
-
-  start_timer (0);
-
-  acc_wait (1);
-
-  atime = stop_timer (0);
-
-  if (0.010 < atime)
-    {
-      fprintf (stderr, "actual time < delay time\n");
-      abort ();
-    }
-
-  acc_unmap_data (a);
-
-  fini_timers ();
-
-  free (a);
-  acc_free (d_a);
-
-  acc_shutdown (acc_device_nvidia);
-
-  return 0;
-}
-
-/* { dg-output "CheCKpOInT(\n|\r\n|\r).*" } */
-/* { dg-output "unknown async \[0-9\]+" } */
-/* { dg-shouldfail "" } */
diff --git libgomp/testsuite/libgomp.oacc-c-c++-common/lib-79.c libgomp/testsuite/libgomp.oacc-c-c++-common/lib-79.c
index ef3df13ebc91..b2e2687e4e76 100644
--- libgomp/testsuite/libgomp.oacc-c-c++-common/lib-79.c
+++ libgomp/testsuite/libgomp.oacc-c-c++-common/lib-79.c
@@ -122,6 +122,13 @@ main (int argc, char **argv)
 	}
     }
 
+  if (acc_async_test (0) != 0)
+    abort ();
+
+  /* Test unseen async-argument.  */
+  if (acc_async_test (1) != 1)
+    abort ();
+
   acc_wait_async (0, 1);
 
   if (acc_async_test (0) != 0)
@@ -130,6 +137,23 @@ main (int argc, char **argv)
   if (acc_async_test (1) != 0)
     abort ();
 
+  /* Test unseen async-argument.  */
+  {
+    if (acc_async_test (2) != 1)
+      abort ();
+
+    acc_wait_async (2, 1);
+
+    if (acc_async_test (0) != 0)
+      abort ();
+
+    if (acc_async_test (1) != 0)
+      abort ();
+
+    if (acc_async_test (2) != 1)
+      abort ();
+  }
+
   acc_wait (1);
 
   atime = stop_timer (0);
diff --git libgomp/testsuite/libgomp.oacc-fortran/lib-12.f90 libgomp/testsuite/libgomp.oacc-fortran/lib-12.f90
index 6912f67d444e..4cf62f2728ad 100644
--- libgomp/testsuite/libgomp.oacc-fortran/lib-12.f90
+++ libgomp/testsuite/libgomp.oacc-fortran/lib-12.f90
@@ -17,9 +17,14 @@ program main
 
   call acc_wait_async (0, 1)
 
+  ! Test unseen async-argument.
+  if (acc_async_test (2) .neqv. .TRUE.) call abort
+  call acc_wait_async (2, 1)
+
   call acc_wait (1)
 
   if (acc_async_test (0) .neqv. .TRUE.) call abort
   if (acc_async_test (1) .neqv. .TRUE.) call abort
+  if (acc_async_test (2) .neqv. .TRUE.) call abort
 
 end program
