diff --git a/README b/README
index 2e0a0bc7c..dcbce0eab 100644
--- a/README
+++ b/README
@@ -45,4 +45,5 @@ As Skype requires that you accept its license, the plugin is not compiled and en
 ZRTP
 liblinphone-sdk depends on the GNU LIBZRTPCPP extension for ZRTP support.
 As the license of this library is GPLv3+ it is not enabled unless the enable_zrtp=yes option is passed to the make command.
+Add liblinphone-sdk/lib/libzrtpcpp.a to XCode. Define sip property media_encryption to "zrtp" in linphonerc.
 Note that activiting ZRTP makes the license of the whole application GPLv3+.
diff --git a/submodules/externals/srtp b/submodules/externals/srtp
index f21cc2418..daa25fdba 160000
--- a/submodules/externals/srtp
+++ b/submodules/externals/srtp
@@ -1 +1 @@
-Subproject commit f21cc24184a285d0b7fec42dba7851a66f7a94ae
+Subproject commit daa25fdbacb75e2aa99f5fce1bd5836dc616fb42