diff --git a/ChangeLog b/ChangeLog
index 25c161b52b35581ef96eb359cdc17bcc73b67d18..82f49a2af386f6f55fefdb39f2ab4026f5c42170 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+2014-02-12  Niels Möller  <nisse@lysator.liu.se>
+
+	* eax.h (EAX_DIGEST_SIZE): New constant.
+	* gcm.h (GCM_DIGEST_SIZE): Likewise.
+
 2014-02-10  Niels Möller  <nisse@lysator.liu.se>
 
 	* chacha-set-nonce.c (chacha_set_nonce): Renamed file and
diff --git a/eax.h b/eax.h
index 988071ddf683dc9bf4c63d8dffd56a7f54793ded..23f62beeff31361969803a228cd0dd005f732868 100644
--- a/eax.h
+++ b/eax.h
@@ -51,6 +51,7 @@ extern "C" {
    this in naming? */
 
 #define EAX_BLOCK_SIZE 16
+#define EAX_DIGEST_SIZE 16
 
 /* Values independent of message and nonce */
 struct eax_key
diff --git a/gcm.h b/gcm.h
index bee453184d6b63e77f6ffd29e079fe93d15ec4c0..9c956ced73284d7bf41c33f69a835a78e6c5796b 100644
--- a/gcm.h
+++ b/gcm.h
@@ -75,7 +75,7 @@ extern "C" {
 
 #define GCM_BLOCK_SIZE 16
 #define GCM_IV_SIZE (GCM_BLOCK_SIZE - 4)
-
+#define GCM_DIGEST_SIZE 16
 #define GCM_TABLE_BITS 8
 
 /* Hashing subkey */