diff --git a/rebar.config b/rebar.config
index 9a3d782..98bf42f 100644
--- a/rebar.config
+++ b/rebar.config
@@ -12,7 +12,7 @@
           {ref, "818ce33"}}},
         {gmhive_worker, {git, "https://git.qpq.swiss/QPQ-AG/gmhive_worker", {ref, "708f1a6"}}},
         {gmconfig, {git, "https://git.qpq.swiss/QPQ-AG/gmconfig.git",
-                    {ref, "32c1ed5c4b"}}},
+                    {ref, "38620ff9e2"}}},
         {gproc, "1.0.0"},
         {setup, {git, "https://github.com/uwiger/setup", {ref, "3ad83ed"}}}
        ]}.
diff --git a/rebar.lock b/rebar.lock
index ce26544..133991e 100644
--- a/rebar.lock
+++ b/rebar.lock
@@ -22,12 +22,8 @@
   0},
  {<<"gmconfig">>,
   {git,"https://git.qpq.swiss/QPQ-AG/gmconfig.git",
-      {ref,"32c1ed5c4bc0913adc175fb18b1c9251acc7b606"}},
+      {ref,"38620ff9e2289dff121377c382e4d5b08c719d87"}},
   0},
- {<<"gmcuckoo">>,
-  {git,"https://git.qpq.swiss/QPQ-AG/gmcuckoo.git",
-      {ref,"9f3aef96d8660e83ef8b5a7ee64908060a8c6572"}},
-  1},
  {<<"gmhive_protocol">>,
   {git,"https://git.qpq.swiss/QPQ-AG/gmhive_protocol.git",
       {ref,"818ce33cc1dec74c020515be48fb548a5207befd"}},
diff --git a/src/gmhc_config.erl b/src/gmhc_config.erl
index 2b21f8b..db5c5c7 100644
--- a/src/gmhc_config.erl
+++ b/src/gmhc_config.erl
@@ -44,12 +44,16 @@ appl_env(K, C) ->
         undefined -> C
     end.
 
+appl_env(bin_dir_hook  , H , C) -> set_bin_dir_hook(H), C;
 appl_env(pubkey        , K , C) -> C#{<<"pubkey">> => K};
 appl_env(extra_pubkeys , Ks, C) -> C#{<<"extra_pubkeys">> => Ks};
 appl_env(pool_admin_url, U , C) -> merge(C, #{<<"pool_admin">> => #{<<"url">> => U}});
 appl_env(workers       , Ws, C) -> C#{<<"workers">> => Ws}.
 
-env_keys() -> [pubkey, extra_pubkeys, pool_admin_url, workers, network].
+set_bin_dir_hook({Mod, F}) when is_atom(Mod), is_atom(F) ->
+    application:set_env(gmhive_worker, bin_dir_hook, {Mod, F}).
+
+env_keys() -> [pubkey, extra_pubkeys, pool_admin_url, workers, network, bin_dir_hook].
 
 cpath([<<"pubkey">>])                -> [user_config                ];
 cpath([<<"extra_pubkeys">>])         -> [user_config, schema_default];
diff --git a/src/gmhc_config_schema.erl b/src/gmhc_config_schema.erl
index 9bbecb8..e840dd0 100644
--- a/src/gmhc_config_schema.erl
+++ b/src/gmhc_config_schema.erl
@@ -66,7 +66,7 @@ pool_admin() ->
 workers() ->
     array(
       #{default => [#{executable => <<"mean29-generic">>,
-                      executable_group => <<"aecuckoo">>}],
+                      executable_group => <<"cpu">>}],
         description =>
             <<"Definitions of workers' configurations. If no worker are configured one worker "
               "is used as default, i.e. 'mean29-generic' executable without any extra args.">>},
@@ -83,9 +83,8 @@ workers() ->
                             "from faster CPU supporting AVX2 instructions).">>}),
             executable_group =>
                 str(#{description => <<"Group of executable binaries of the worker.">>,
-                      enum => [ <<"aecuckoo">>, <<"aecuckooprebuilt">>,
-                                <<"gmcuckoo">>, <<"cuda">>, <<"gajumine">> ],
-                      default => <<"aecuckoo">>}),
+                      enum => [ <<"cpu">>, <<"cuda">> ],
+                      default => <<"cpuo">>}),
             extra_args =>
                 str(#{description => <<"Extra arguments to pass to the worker executable binary. "
                                        "The safest choice is specifying no arguments i.e. empty string.">>,
diff --git a/src/gmhc_workers.erl b/src/gmhc_workers.erl
index 2d2eaff..faf7612 100644
--- a/src/gmhc_workers.erl
+++ b/src/gmhc_workers.erl
@@ -16,7 +16,7 @@
 
 -include_lib("kernel/include/logger.hrl").
 
--define(DEFAULT_EXECUTABLE_GROUP   , <<"gajumine">>).
+-define(DEFAULT_EXECUTABLE_GROUP   , <<"cpu">>).
 -define(DEFAULT_EXTRA_ARGS         , <<>>).
 -define(DEFAULT_HEX_ENCODED_HEADER , false).
 -define(DEFAULT_REPEATS            , 1).