diff --git a/libs/netpgp/src/keyring.c b/libs/netpgp/src/keyring.c
index c6a27d58..11b13da5 100644
--- a/libs/netpgp/src/keyring.c
+++ b/libs/netpgp/src/keyring.c
@@ -862,7 +862,7 @@ pgp_add_selfsigned_userid(pgp_key_t *skey, pgp_key_t *pkey, const uint8_t *useri
 	pgp_add_key_expiration_time(sig, key_expiry);
 	pgp_add_issuer_keyid(sig, skey->pubkeyid);
 	pgp_add_primary_userid(sig, 1);
-    pgp_add_key_flags(sig, PGP_KEYFLAG_SIGN_DATA|PGP_KEYFLAG_ENC_COMM);
+    pgp_add_key_flags(sig, PGP_KEYFLAG_SIGN_DATA|PGP_KEYFLAG_CERT_KEYS); // Edit for Autocrypt/Delta Chat: our primary key should be able to SIGN+CERTIFY (original was SIGN+ENC_COMM) (maybe we should create a copy of this functions to be future-save on netpgp-updates)
     pgp_add_key_prefs(sig);
     pgp_add_key_features(sig);
 
diff --git a/libs/netpgp/src/signature.c b/libs/netpgp/src/signature.c
index 4a8ec2cb..d806c88c 100644
--- a/libs/netpgp/src/signature.c
+++ b/libs/netpgp/src/signature.c
@@ -921,15 +921,15 @@ pgp_add_key_prefs(pgp_create_sig_t *sig)
         /* Hash algo prefs */
         pgp_write_ss_header(sig->output, 6, PGP_PTAG_SS_PREFERRED_HASH) &&
         pgp_write_scalar(sig->output, PGP_HASH_SHA256, 1) &&
-        pgp_write_scalar(sig->output, PGP_HASH_SHA1, 1) &&
         pgp_write_scalar(sig->output, PGP_HASH_SHA384, 1) &&
         pgp_write_scalar(sig->output, PGP_HASH_SHA512, 1) &&
         pgp_write_scalar(sig->output, PGP_HASH_SHA224, 1) &&
+        pgp_write_scalar(sig->output, PGP_HASH_SHA1, 1) && // Edit for Autocrypt/Delta Chat: due to the weak SHA1, it should not be preferred
 
         /* Compression algo prefs */
-        pgp_write_ss_header(sig->output, 3, PGP_PTAG_SS_PREF_COMPRESS) &&
-        pgp_write_scalar(sig->output, PGP_C_ZLIB, 1) &&
-        pgp_write_scalar(sig->output, PGP_C_BZIP2, 1);
+        pgp_write_ss_header(sig->output, 2/*1+number of following items*/, PGP_PTAG_SS_PREF_COMPRESS) &&
+        pgp_write_scalar(sig->output, PGP_C_ZLIB, 1) /*&& -- not sure if Delta Chat will support bzip2 on all platforms, however, this is not that important as typical files are compressed themselves and text is not that big
+        pgp_write_scalar(sig->output, PGP_C_BZIP2, 1) -- if you re-enable this, do not forget to modifiy the header count*/;
 }
 
 unsigned
diff --git a/src/mre2ee_driver_openssl.c b/src/mre2ee_driver_openssl.c
index 8ac1736c..c6a8b771 100644
--- a/src/mre2ee_driver_openssl.c
+++ b/src/mre2ee_driver_openssl.c
@@ -163,9 +163,9 @@ int mre2ee_driver_create_keypair(mrmailbox_t* mailbox, const char* addr, mrkey_t
 		pgp_add_creation_time(sig, time(NULL));
 		pgp_add_key_expiration_time(sig, 0);
 		pgp_add_issuer_keyid(sig, seckey.pubkeyid);
-		pgp_add_primary_userid(sig, 1);
-		pgp_add_key_flags(sig, PGP_KEYFLAG_SIGN_DATA|PGP_KEYFLAG_ENC_COMM);
-		pgp_add_key_prefs(sig);
+		//pgp_add_primary_userid(sig, 1); -- seems not be needed for "ubkey Binding Signature"
+		pgp_add_key_flags(sig, PGP_KEYFLAG_ENC_STORAGE|PGP_KEYFLAG_ENC_COMM);
+		//pgp_add_key_prefs(sig); -- algo/hash/compression preferences seems not to be required for subkeys
 		pgp_add_key_features(sig);
 
 		pgp_end_hashed_subpkts(sig);