2 files changed, 11 insertions, 5 deletions

diff --git a/src/cadet/gnunet-service-cadet_tunnel.c b/src/cadet/gnunet-service-cadet_tunnel.c
index 7c420843e..f1cbad63c 100644
--- a/src/cadet/gnunet-service-cadet_tunnel.c
+++ b/src/cadet/gnunet-service-cadet_tunnel.c
@@ -2184,8 +2184,10 @@ GCT_init (const struct GNUNET_CONFIGURATION_Handle *c,
 
   LOG (GNUNET_ERROR_TYPE_DEBUG, "init\n");
 
-  expected_overhead =
-    sizeof (struct GNUNET_CADET_Encrypted) + sizeof (struct GNUNET_CADET_Data);
+  expected_overhead = 0;
+  expected_overhead += sizeof (struct GNUNET_CADET_Encrypted);
+  expected_overhead += sizeof (struct GNUNET_CADET_Data);
+  expected_overhead += sizeof (struct GNUNET_CADET_ACK);
   GNUNET_assert (GNUNET_CONSTANTS_CADET_P2P_OVERHEAD == expected_overhead);
 
   if (GNUNET_OK !=
diff --git a/src/include/gnunet_constants.h b/src/include/gnunet_constants.h
index 9ef500388..36fa72bd0 100644
--- a/src/include/gnunet_constants.h
+++ b/src/include/gnunet_constants.h
@@ -121,10 +121,14 @@ extern "C"
 #define GNUNET_CONSTANTS_MAX_ENCRYPTED_MESSAGE_SIZE (63 * 1024)
 
 /**
- * Size of the CADET message overhead.
- * See gnunet-service-cadet_tunnel.c: GCT_init for more info.
+ * Size of the CADET message overhead:
+ * + sizeof (struct GNUNET_CADET_Encrypted)
+ * + sizeof (struct GNUNET_CADET_Data)
+ * + sizeof (struct GNUNET_CADET_ACK))
+ *
+ * Checked for correcteness in gnunet-service-cadet_tunnel.c: GCT_init().
  */
-#define GNUNET_CONSTANTS_CADET_P2P_OVERHEAD 92
+#define GNUNET_CONSTANTS_CADET_P2P_OVERHEAD 132
 
 /**
  * Maximum message size that can be sent on CADET.