diff --git a/configure.ac b/configure.ac
index 0b82d3778adeb4647fa6471e346b7720df804510..8f7a1123dfc0f5ec2b5a7568de3c1f593a413f9f 100644
--- a/configure.ac
+++ b/configure.ac
@@ -2,8 +2,8 @@ AC_PREREQ([2.59])
 
 # Be sure to update ABI version also if anything changes that might require
 # recompiling plugins. Most importantly that means if any structs are changed.
-AC_INIT([Pigeonhole], [0.5.devel], [dovecot@dovecot.org], [dovecot-2.2-pigeonhole])
-AC_DEFINE_UNQUOTED([PIGEONHOLE_ABI_VERSION], "0.4.ABIv2($PACKAGE_VERSION)", [Pigeonhole ABI version])
+AC_INIT([Pigeonhole], [0.6.devel], [dovecot@dovecot.org], [dovecot-2.2-pigeonhole])
+AC_DEFINE_UNQUOTED([PIGEONHOLE_ABI_VERSION], "0.6.ABIv0($PACKAGE_VERSION)", [Pigeonhole ABI version])
 
 AC_CONFIG_AUX_DIR([.])
 AC_CONFIG_SRCDIR([src])