diff --git a/ChangeLog b/ChangeLog
index e58899bb31530a212e9242125eb860492a4cce2b..dbcb5435a73cc40c7b9808f8bd079d37df4137e7 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,8 @@
 2014-12-08  Niels Möller  <nisse@lysator.liu.se>
 
+	* configure.ac (LIBNETTLE_MAJOR): Bump major number, now 6.
+	(LIBHOGWEED_MAJOR): Bump major number, now 5.
+
 	From Nikos Mavrogiannopoulos. Support for versioned symbols.
 	* aclocal.m4 (LD_VERSION_SCRIPT): New macro. Substitute
 	EXTRA_LINKER_FLAGS and EXTRA_HOGWEED_LINKER_FLAGS.
diff --git a/configure.ac b/configure.ac
index 33c16e1319d9ff4a456fda510f59d430f894429e..5a3664244b2d54a01a5a637fc8b8879990f2e34f 100644
--- a/configure.ac
+++ b/configure.ac
@@ -10,10 +10,10 @@ AC_CONFIG_AUX_DIR([.])
 
 AC_CONFIG_HEADER([config.h])
 
-LIBNETTLE_MAJOR=5
+LIBNETTLE_MAJOR=6
 LIBNETTLE_MINOR=0
 
-LIBHOGWEED_MAJOR=4
+LIBHOGWEED_MAJOR=5
 LIBHOGWEED_MINOR=0
 
 AC_CANONICAL_HOST