diff --git a/src/target/arm_adi_v5.c b/src/target/arm_adi_v5.c
index 1a8645897..ba5db3b13 100644
--- a/src/target/arm_adi_v5.c
+++ b/src/target/arm_adi_v5.c
@@ -305,8 +305,9 @@ int swjdp_transaction_endcheck(struct swjdp_common *swjdp)
 			}
 			else
 			{
-				LOG_WARNING("Invalid ACK "
-						"in JTAG-DP transaction");
+				LOG_WARNING("Invalid ACK %#x"
+						"in JTAG-DP transaction",
+						swjdp->ack);
 				return ERROR_JTAG_DEVICE_ERROR;
 			}