diff --git a/PROTOCOL b/PROTOCOL
index 546998b78..8117d0043 100644
--- a/PROTOCOL
+++ b/PROTOCOL
@@ -420,6 +420,13 @@ memfd support only to 10.0+ clients.
 
 Check commit 451d1d676237c81 for further details.
 
+## v33, implemented by >= 13.0
+
+Added two values to the pa_encoding_t enum:
+
+    PA_ENCODING_TRUEHD_IEC61937 := 7
+    PA_ENCODING_DTSHD_IEC61937 := 8
+
 #### If you just changed the protocol, read this
 ## module-tunnel depends on the sink/source/sink-input/source-input protocol
 ## internals, so if you changed these, you might have broken module-tunnel.
diff --git a/configure.ac b/configure.ac
index 681d78cd3..8890aa15f 100644
--- a/configure.ac
+++ b/configure.ac
@@ -40,7 +40,7 @@ AC_SUBST(PA_MINOR, pa_minor)
 AC_SUBST(PA_MAJORMINOR, pa_major.pa_minor)
 
 AC_SUBST(PA_API_VERSION, 12)
-AC_SUBST(PA_PROTOCOL_VERSION, 32)
+AC_SUBST(PA_PROTOCOL_VERSION, 33)
 
 # The stable ABI for client applications, for the version info x:y:z
 # always will hold y=z