diff --git a/src/vnet/ipsec/ah_encrypt.c b/src/vnet/ipsec/ah_encrypt.c
index 898c0f2..6619d87 100644
--- a/src/vnet/ipsec/ah_encrypt.c
+++ b/src/vnet/ipsec/ah_encrypt.c
@@ -263,17 +263,19 @@
 
 	  u8 sig[64];
 	  memset (sig, 0, sizeof (sig));
-	  u8 *digest =
-	    vlib_buffer_get_current (i_b0) + ip_hdr_size + icv_size;
-	  memset (digest, 0, icv_size);
+	  u8 *digest = NULL;
+	  {
+	    digest = vlib_buffer_get_current (i_b0) + ip_hdr_size + icv_size;
+	    memset (digest, 0, icv_size);
+	  }
 
-	  unsigned size = hmac_calc (sa0->integ_alg, sa0->integ_key,
-				     sa0->integ_key_len,
-				     vlib_buffer_get_current (i_b0),
-				     i_b0->current_length, sig, sa0->use_esn,
-				     sa0->seq_hi);
+	  hmac_calc (sa0->integ_alg, sa0->integ_key,
+		     sa0->integ_key_len,
+		     (u8 *) vlib_buffer_get_current (i_b0),
+		     i_b0->current_length, sig, sa0->use_esn, sa0->seq_hi);
 
-	  memcpy (digest, sig, size);
+	  memcpy (digest, (char *) &sig[0], 12);
+
 	  if (PREDICT_FALSE (is_ipv6))
 	    {
 	    }
@@ -285,7 +287,7 @@
 	    }
 
 	  if (transport_mode)
-	    vlib_buffer_advance (i_b0, -sizeof (ethernet_header_t));
+	    vlib_buffer_advance (i_b0, -sizeof (ethernet_header_t));;
 
 	trace:
 	  if (PREDICT_FALSE (i_b0->flags & VLIB_BUFFER_IS_TRACED))