diff --git a/CMakeLists.txt b/CMakeLists.txt
index c42c3241..6c83e9f8 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -745,7 +745,7 @@ else ()
                           COMPILE_DEFINITIONS "DLL_EXPORT"
                           PUBLIC_HEADER "${public_headers}"
                           VERSION ${ZMQ_VERSION}
-                          SOVERSION "5.1.0"
+                          SOVERSION "5.1.1"
                           OUTPUT_NAME "libzmq"
                           PREFIX "")
     if (ZMQ_BUILD_FRAMEWORK)
diff --git a/NEWS b/NEWS
index 1887f5de..86aab0ca 100644
--- a/NEWS
+++ b/NEWS
@@ -1,4 +1,4 @@
-0MQ version 4.2.1 stable, released on 201x/xx/xx
+0MQ version 4.2.1 stable, released on 2016/12/31
 =============================================
 
 * New DRAFT (see NEWS for 4.2.0) Socket Monitor events:
diff --git a/configure.ac b/configure.ac
index a8c9c25d..915d7953 100644
--- a/configure.ac
+++ b/configure.ac
@@ -38,9 +38,10 @@ AC_SUBST(PACKAGE_VERSION)
 # ZeroMQ version 4.0: 4:0:0 (ABI version 4)
 # ZeroMQ version 4.1: 5:0:0 (ABI version 5)
 # ZeroMQ version 4.2.0: 6:0:1 (ABI version 5)
+# ZeroMQ version 4.2.1: 6:1:1 (ABI version 5)
 #
 # libzmq -version-info current:revision:age
-LTVER="6:0:1"
+LTVER="6:1:1"
 AC_SUBST(LTVER)
 
 # Take a copy of original flags