diff --git a/sys/kern/subr_intr.c b/sys/kern/subr_intr.c
--- a/sys/kern/subr_intr.c
+++ b/sys/kern/subr_intr.c
@@ -468,13 +468,10 @@
 
 	mtx_assert(&isrc_table_lock, MA_OWNED);
 
-	if (isrc->isrc_irq >= intr_nirq)
-		return (EINVAL);
-	if (irq_sources[isrc->isrc_irq] != isrc)
-		return (EINVAL);
-
-	irq_sources[isrc->isrc_irq] = NULL;
-	isrc->isrc_irq = INTR_IRQ_INVALID;	/* just to be safe */
+	if (isrc->isrc_irq < intr_nirq) {
+		if (irq_sources[isrc->isrc_irq] == isrc)
+			irq_sources[isrc->isrc_irq] = NULL;
+		isrc->isrc_irq = INTR_IRQ_INVALID;	/* mark removed */
 
 	/*
 	 * If we are recovering from the state irq_sources table is full,
@@ -482,8 +479,9 @@
 	 * will ensure maximum separation of allocation order from release
 	 * order.
 	 */
-	if (irq_next_free >= intr_nirq)
-		irq_next_free = 0;
+		if (irq_next_free >= intr_nirq)
+			irq_next_free = 0;
+	}
 
 	return (0);
 }
@@ -537,7 +535,11 @@
 		isrc_release_counters(isrc);
 	error = isrc_free_irq(isrc);
 	mtx_unlock(&isrc_table_lock);
-	return (error);
+
+	if (error != 0)
+		return (error);
+
+	return (intr_event_destroy(isrc->isrc_event));
 }
 
 #ifdef SMP