diff --git a/lib/extensions/ras/ras_common.c b/lib/extensions/ras/ras_common.c
index 36f9a95..622879e 100644
--- a/lib/extensions/ras/ras_common.c
+++ b/lib/extensions/ras/ras_common.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2018-2019, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2018-2021, ARM Limited and Contributors. All rights reserved.
  * Copyright (c) 2020, NVIDIA Corporation. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
@@ -139,7 +139,7 @@
 	assert(ras_interrupt_mappings.num_intrs > 0UL);
 
 	start = 0;
-	end = (int) ras_interrupt_mappings.num_intrs;
+	end = (int)ras_interrupt_mappings.num_intrs - 1;
 	while (start <= end) {
 		mid = ((end + start) / 2);
 		if (intr_raw == ras_inrs[mid].intr_number) {