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
@@ -415,6 +415,20 @@
 	return (EINVAL);
 }
 
+/*
+ *  Destroy interrupt event for interrupt source.
+ */
+static int
+isrc_event_destroy(struct intr_irqsrc *isrc)
+{
+	int rc = intr_event_destroy(isrc->isrc_event);
+
+	if (rc == 0)
+		isrc->isrc_event = NULL;
+
+	return (rc);
+}
+
 /*
  *  Alloc unique interrupt number (resource handle) for interrupt source.
  *
@@ -467,12 +481,11 @@
 	mtx_assert(&isrc_table_lock, MA_OWNED);
 
 	if (isrc->isrc_irq >= intr_nirq)
-		return (EINVAL);
-	if (irq_sources[isrc->isrc_irq] != isrc)
-		return (EINVAL);
+		return (0);
 
-	irq_sources[isrc->isrc_irq] = NULL;
-	isrc->isrc_irq = INTR_IRQ_INVALID;	/* just to be safe */
+	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,
@@ -535,7 +548,11 @@
 		isrc_release_counters(isrc);
 	error = isrc_free_irq(isrc);
 	mtx_unlock(&isrc_table_lock);
-	return (error);
+
+	if (error != 0)
+		return (error);
+
+	return (isrc_event_destroy(isrc));
 }
 
 #ifdef SMP
@@ -702,24 +719,7 @@
 
 	return (0);
 }
-#ifdef notyet
-/*
- *  Destroy interrupt event for interrupt source.
- */
-static void
-isrc_event_destroy(struct intr_irqsrc *isrc)
-{
-	struct intr_event *ie;
-
-	mtx_lock(&isrc_table_lock);
-	ie = isrc->isrc_event;
-	isrc->isrc_event = NULL;
-	mtx_unlock(&isrc_table_lock);
 
-	if (ie != NULL)
-		intr_event_destroy(ie);
-}
-#endif
 /*
  *  Add handler to interrupt source.
  */