diff --git a/share/man/man4/nvme.4 b/share/man/man4/nvme.4
--- a/share/man/man4/nvme.4
+++ b/share/man/man4/nvme.4
@@ -239,6 +239,15 @@
 See
 .Xr ahci 4
 for more details.
+.Sh DIAGNOSTICS
+.Bl -diag
+.It "nvme%d: System interrupt issues?"
+The driver found a timed-out transaction had a pending completion record,
+indicating an interrupt had not been delivered.
+The system is either not configuring interrupts properly, or the system drops
+them under load.
+This message will appear at most once per boot per controller.
+.El
 .Sh SEE ALSO
 .Xr nda 4 ,
 .Xr nvd 4 ,
diff --git a/sys/dev/nvme/nvme_private.h b/sys/dev/nvme/nvme_private.h
--- a/sys/dev/nvme/nvme_private.h
+++ b/sys/dev/nvme/nvme_private.h
@@ -303,6 +303,7 @@
 
 	bool				is_failed;
 	bool				is_dying;
+	bool				isr_warned;
 	STAILQ_HEAD(, nvme_request)	fail_req;
 
 	/* Host Memory Buffer */
diff --git a/sys/dev/nvme/nvme_qpair.c b/sys/dev/nvme/nvme_qpair.c
--- a/sys/dev/nvme/nvme_qpair.c
+++ b/sys/dev/nvme/nvme_qpair.c
@@ -1138,7 +1138,10 @@
 		 * at least 1/2s old.  Call the completion ISR to catch 'missed'
 		 * interrupts.
 		 */
-		_nvme_qpair_process_completions(qpair);
+		if (_nvme_qpair_process_completions(qpair) && !ctrlr->isr_warned) {
+			nvme_printf(ctrlr, "System interrupt issues?\n");
+			ctrlr->isr_warned = true;
+		}
 
 		/*
 		 * Now that we've run the ISR, re-rheck to see if there's any