diff --git a/configure.ac b/configure.ac
index 58ce8e326a..4cfd7f1e23 100644
--- a/configure.ac
+++ b/configure.ac
@@ -8,11 +8,11 @@ AC_PREREQ(2.54)
 
 m4_define([gimp_major_version], [2])
 m4_define([gimp_minor_version], [8])
-m4_define([gimp_micro_version], [20])
+m4_define([gimp_micro_version], [21])
 m4_define([gimp_real_version],
           [gimp_major_version.gimp_minor_version.gimp_micro_version])
 m4_define([gimp_version], [gimp_real_version])
-m4_define([gimp_interface_age], [20])
+m4_define([gimp_interface_age], [21])
 m4_define([gimp_binary_age],
           [m4_eval(100 * gimp_minor_version + gimp_micro_version)])