diff --git a/rebar.config b/rebar.config
index 4e1a926..aba57e9 100644
--- a/rebar.config
+++ b/rebar.config
@@ -4,6 +4,7 @@
 
 {deps, [ {aebytecode, {git, "https://github.com/aeternity/aebytecode.git", {ref,"c63ac88"}}}
        , {getopt, "1.0.1"}
+       , {eblake2, "1.0.0"}
        , {jsx, {git, "https://github.com/talentdeficit/jsx.git",
                      {tag, "2.8.0"}}}
        ]}.
diff --git a/src/aeso_ast_to_fcode.erl b/src/aeso_ast_to_fcode.erl
index c20e569..16b0309 100644
--- a/src/aeso_ast_to_fcode.erl
+++ b/src/aeso_ast_to_fcode.erl
@@ -137,6 +137,7 @@
                   vars       => [var_name()],
                   functions  := #{ fun_name() => fun_def() } }.
 
+-define(HASH_BYTES, 32).
 %% -- Entrypoint -------------------------------------------------------------
 
 %% Main entrypoint. Takes typed syntax produced by aeso_ast_infer_types:infer/1,2
@@ -829,8 +830,8 @@ event_function(_Env = #{event_type := {variant_t, EventCons}}, EventType = {vari
              || {I, {constr_t, Ann, {con, _, Name}, _}} <- indexed(EventCons) ],
     Arities = [length(Ts) || Ts <- FCons],
     Case = fun({Name, Tag, Ixs}) ->
-                %% TODO: precompute (needs dependency)
-                Hash = {op, crypto_sha3, [{lit, {string, list_to_binary(Name)}}]},
+                {ok, HashValue} = eblake2:blake2b(?HASH_BYTES, list_to_binary(Name)),
+                Hash = {lit, {bytes, HashValue}},
                 Vars = [ "arg" ++ integer_to_list(I) || I <- lists:seq(1, length(Ixs)) ],
                 IVars = lists:zip(Ixs, Vars),
                 Payload =
diff --git a/src/aeso_builtins.erl b/src/aeso_builtins.erl
index daf638f..93c1c57 100644
--- a/src/aeso_builtins.erl
+++ b/src/aeso_builtins.erl
@@ -62,6 +62,8 @@ v(X) when is_list(X) -> #var_ref{name = X}.
 option_none()  -> {tuple, [{integer, 0}]}.
 option_some(X) -> {tuple, [{integer, 1}, X]}.
 
+-define(HASH_BYTES, 32).
+
 -define(call(Fun, Args), #funcall{ function = #var_ref{ name = {builtin, Fun} }, args = Args }).
 -define(I(X), {integer, X}).
 -define(V(X), v(X)).
@@ -93,12 +95,6 @@ operand(A) when is_atom(A) -> v(A);
 operand(I) when is_integer(I) -> {integer, I};
 operand(T) -> T.
 
-str_to_icode(String) when is_list(String) ->
-    str_to_icode(list_to_binary(String));
-str_to_icode(BinStr) ->
-    Cpts = [size(BinStr) | aeb_memory:binary_to_words(BinStr)],
-    #tuple{ cpts = [ #integer{value = X} || X <- Cpts ] }.
-
 check_event_type(Icode) ->
     case maps:get(event_type, Icode) of
         {variant_t, Cons} ->
@@ -192,7 +188,8 @@ builtin_event(EventT) ->
             Types     = [ T || {_Ix, T} <- IxTypes ],
             Indexed   = [ Ix(Type, Var) || {Var, {indexed, Type}} <- lists:zip(ArgPats(Types), IxTypes) ],
             Data      = [ {Type, Var} || {Var, {notindexed, Type}} <- lists:zip(ArgPats(Types), IxTypes) ],
-            EvtIndex  = {unop, 'sha3', str_to_icode(Con)},
+            {ok, <<EvtIndexN:256>>} = eblake2:blake2b(?HASH_BYTES, list_to_binary(Con)),
+            EvtIndex  = {integer, EvtIndexN},
             {event, lists:reverse(Indexed) ++ [EvtIndex], Payload(Data)}
         end,
     Pat = fun(Tag, Types) -> {tuple, [{integer, Tag} | ArgPats(Types)]} end,
diff --git a/src/aesophia.app.src b/src/aesophia.app.src
index 1547ee4..6b16408 100644
--- a/src/aesophia.app.src
+++ b/src/aesophia.app.src
@@ -8,7 +8,8 @@
     jsx,
     syntax_tools,
     getopt,
-    aebytecode
+    aebytecode,
+    eblake2
    ]},
   {env,[]},
   {modules, []},