diff --git a/NEWS b/NEWS
index 7276a7f1..77322ca9 100644
--- a/NEWS
+++ b/NEWS
@@ -6,6 +6,10 @@ vim: spelllang=en spell tw=78
 
 -------------------------------------------------------------------------------
 
+Changes in 1.6.0-rc1:
+
+* Support for multiple mailbox protocols at the same time
+
 Changes since 1.5.2:
 
 * Fixed FoE timeout calculation bug.
diff --git a/configure.ac b/configure.ac
index dc45ec73..292f2b16 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1,8 +1,6 @@
 #------------------------------------------------------------------------------
 #
-#  $Id$
-#
-#  Copyright (C) 2006-2012  Florian Pose, Ingenieurgemeinschaft IgH
+#  Copyright (C) 2006-2022  Florian Pose, Ingenieurgemeinschaft IgH
 #
 #  This file is part of the IgH EtherCAT Master.
 #
@@ -39,7 +37,7 @@ AC_PREREQ(2.59)
 # - Update version number below
 # - make dist-bzip2
 #
-AC_INIT([ethercat],[1.5.2],[fp@igh-essen.com])
+AC_INIT([ethercat],[1.6.0-rc1],[fp@igh.de])
 AC_CONFIG_AUX_DIR([autoconf])
 AM_INIT_AUTOMAKE([-Wall -Wno-override -Werror dist-bzip2 subdir-objects])
 m4_ifdef([AM_SILENT_RULES], [AM_SILENT_RULES([yes])])
diff --git a/documentation/ethercat_doc.tex b/documentation/ethercat_doc.tex
index 6e03a25b..e6d5a303 100644
--- a/documentation/ethercat_doc.tex
+++ b/documentation/ethercat_doc.tex
@@ -2,8 +2,6 @@
 %
 %  IgH EtherCAT Master Documentation
 %
-%  $Id$
-%
 %  vi: spell spelllang=en tw=78
 %
 %------------------------------------------------------------------------------
@@ -60,7 +58,7 @@
 
 \rcsInfo $RCSId$
 
-\newcommand{\masterversion}{1.5.2}
+\newcommand{\masterversion}{1.6.0}
 \newcommand{\linenum}[1]{\normalfont\textcircled{\tiny #1}}
 
 \makeindex
diff --git a/include/ecrt.h b/include/ecrt.h
index 21339bff..b7b96b80 100644
--- a/include/ecrt.h
+++ b/include/ecrt.h
@@ -145,15 +145,20 @@
 
 /** EtherCAT realtime interface minor version number.
  */
-#define ECRT_VER_MINOR 5
+#define ECRT_VER_MINOR 6
+
+/** EtherCAT realtime interface patchlevel number.
+ */
+#define ECRT_VER_PATCH 0
 
 /** EtherCAT realtime interface version word generator.
  */
-#define ECRT_VERSION(a, b) (((a) << 8) + (b))
+#define ECRT_VERSION(a, b, c) (((a) << 16) + ((b) << 8) + (c))
 
 /** EtherCAT realtime interface version word.
  */
-#define ECRT_VERSION_MAGIC ECRT_VERSION(ECRT_VER_MAJOR, ECRT_VER_MINOR)
+#define ECRT_VERSION_MAGIC \
+     ECRT_VERSION(ECRT_VER_MAJOR, ECRT_VER_MINOR, ECRT_VER_PATCH)
 
 /******************************************************************************
  * Feature flags
diff --git a/master/ioctl.h b/master/ioctl.h
index 76eef5de..054b3098 100644
--- a/master/ioctl.h
+++ b/master/ioctl.h
@@ -47,7 +47,7 @@
  *
  * Increment this when changing the ioctl interface!
  */
-#define EC_IOCTL_VERSION_MAGIC 31
+#define EC_IOCTL_VERSION_MAGIC 37
 
 // Command-line tool
 #define EC_IOCTL_MODULE                EC_IOR(0x00, ec_ioctl_module_t)