diff --git a/Makefile b/Makefile
index a6ef4631..f16bb612 100644
--- a/Makefile
+++ b/Makefile
@@ -14,7 +14,7 @@
 #
 
 PROGNAME    = afl
-VERSION     = 2.11b
+VERSION     = 2.12b
 
 PREFIX     ?= /usr/local
 BIN_PATH    = $(PREFIX)/bin
diff --git a/afl-tmin.c b/afl-tmin.c
index f2ddc6e2..403724c6 100644
--- a/afl-tmin.c
+++ b/afl-tmin.c
@@ -533,7 +533,7 @@ static void minimize(char** argv) {
   alpha_del1   = 0;
   syms_removed = 0;
 
-  memset(alpha_map, 0, 256);
+  memset(alpha_map, 0, 256 * sizeof(u32));
 
   for (i = 0; i < in_len; i++) {
     if (!alpha_map[in_data[i]]) alpha_size++;
diff --git a/docs/ChangeLog b/docs/ChangeLog
index 154373d7..ed6912f6 100644
--- a/docs/ChangeLog
+++ b/docs/ChangeLog
@@ -16,6 +16,13 @@ Not sure if you should upgrade? The lowest currently recommended version
 is 2.07b. If you're stuck on an earlier release, it's strongly advisable
 to get on with the times.
 
+--------------
+Version 2.12b:
+--------------
+
+  - Fixed a minor issue in afl-tmin that can make alphabet minimization less
+    efficient during passes > 1. Spotted by Daniel Binderman.
+
 --------------
 Version 2.11b:
 --------------
diff --git a/docs/README b/docs/README
index d438adca..642e57b7 100644
--- a/docs/README
+++ b/docs/README
@@ -439,6 +439,7 @@ bug reports, or patches from:
   Guillaume Endignoux                   ilovezfs
   Daniel Godas-Lopez                    Franjo Ivancic
   Austin Seipp                          Daniel Komaromy
+  Daniel Binderman
 
 Thank you!