diff --git a/include/aeb_fate_data.hrl b/include/aeb_fate_data.hrl
index 3160b4d..8c07896 100644
--- a/include/aeb_fate_data.hrl
+++ b/include/aeb_fate_data.hrl
@@ -5,6 +5,7 @@
 -define(FATE_LIST_T,      list()).
 -define(FATE_UNIT_T,      {tuple, {}}).
 -define(FATE_MAP_T,       #{ fate_type() => fate_type() }).
+-define(FATE_STORE_MAP_T, {store_map, #{ fate_type() => fate_type() | ?FATE_MAP_TOMBSTONE }, integer()}).
 -define(FATE_STRING_T,    binary()).
 -define(FATE_ADDRESS_T,   {address, <<_:256>>}).
 -define(FATE_BYTES_T(N),  {bytes, binary()}).
@@ -20,6 +21,10 @@
 -define(IS_FATE_INTEGER(X), (is_integer(X))).
 -define(IS_FATE_LIST(X),    (is_list(X))).
 -define(IS_FATE_STRING(X),  (is_binary(X))).
+-define(IS_FATE_STORE_MAP(X), (is_tuple(X) andalso tuple_size(X) == 3
+                                           andalso store_map == element(1, X)
+                                           andalso is_map(element(2, X))
+                                           andalso is_integer(element(3, X)))).
 -define(IS_FATE_MAP(X),     (is_map(X))).
 -define(IS_FATE_TUPLE(X),   (is_tuple(X) andalso (tuple == element(1, X) andalso is_tuple(element(2, X))))).
 -define(IS_FATE_ADDRESS(X), (is_tuple(X) andalso (address == element(1, X) andalso is_binary(element(2, X))))).
@@ -50,6 +55,8 @@
 -define(FATE_CHANNEL(X),   {channel, X}).
 -define(FATE_BITS(B),      {bits, B}).
 -define(FATE_TYPEREP(T),   {typerep, T}).
+-define(FATE_STORE_MAP(Cache, Id), {store_map, Cache, Id}).
+-define(FATE_MAP_TOMBSTONE, '__DELETED__').
 
 -define(FATE_INTEGER_VALUE(X), (X)).
 -define(FATE_BOOLEAN_VALUE(X), (X)).
@@ -63,6 +70,8 @@
 -define(FATE_CHANNEL_VALUE(X), (element(2, X))).
 -define(FATE_BITS_VALUE(X), (element(2, X))).
 -define(FATE_MAP_VALUE(X), (X)).
+-define(FATE_STORE_MAP_CACHE(X), (element(2, X))).
+-define(FATE_STORE_MAP_ID(X), (element(3, X))).
 -define(FATE_MAP_SIZE(X), (map_size(X))).
 -define(FATE_STRING_SIZE(X), (byte_size(X))).
 -define(FATE_TRUE,  true).
diff --git a/src/aeb_fate_data.erl b/src/aeb_fate_data.erl
index 2660386..eb7b54b 100644
--- a/src/aeb_fate_data.erl
+++ b/src/aeb_fate_data.erl
@@ -10,6 +10,7 @@
 -type fate_list()      :: ?FATE_LIST_T.
 -type fate_unit()      :: ?FATE_UNIT_T.
 -type fate_map()       :: ?FATE_MAP_T.
+-type fate_store_map() :: ?FATE_STORE_MAP_T.
 -type fate_string()    :: ?FATE_STRING_T.
 -type fate_address()   :: ?FATE_ADDRESS_T.
 -type fate_hash()      :: ?FATE_BYTES_T(32).
@@ -71,6 +72,7 @@
              , fate_channel/0
              , fate_variant/0
              , fate_map/0
+             , fate_store_map/0
              , fate_bits/0
              , fate_type_type/0
              ]).
@@ -82,6 +84,8 @@
         , make_tuple/1
         , make_string/1
         , make_map/1
+        , make_store_map/1
+        , make_store_map/2
         , make_address/1
         , make_bytes/1
         , make_hash/1
@@ -108,6 +112,8 @@ make_list(L) ->        ?MAKE_FATE_LIST(L).
 make_unit() ->         ?FATE_UNIT.
 make_tuple(T) ->       ?FATE_TUPLE(T).
 make_map(M) ->         ?MAKE_FATE_MAP(M).
+make_store_map(Id) ->  make_store_map(#{}, Id).
+make_store_map(Cache, Id) -> ?FATE_STORE_MAP(Cache, Id).
 make_address(X) ->     ?FATE_ADDRESS(X).
 make_bytes(X) ->       ?FATE_BYTES(X).
 make_hash(X) ->        make_bytes(X).
diff --git a/src/aeb_fate_encoding.erl b/src/aeb_fate_encoding.erl
index 2475c1d..3706322 100644
--- a/src/aeb_fate_encoding.erl
+++ b/src/aeb_fate_encoding.erl
@@ -93,6 +93,7 @@
 %%                                  %% 1000 1111 - FREE (Possibly for bytecode in the future.)
 -define(OBJECT       , 2#10011111). %% 1001 1111 | ObjectType | RLP encoded Array
 -define(VARIANT      , 2#10101111). %% 1010 1111 | [encoded arities] | encoded tag | [encoded values]
+-define(MAP_ID       , 2#10111111). %% 1011 1111 | RLP encoded integer (store map id)
 -define(NEG_BITS     , 2#11001111). %% 1100 1111 | RLP encoded integer (infinite 1:s bitfield)
 -define(EMPTY_MAP    , 2#11011111). %% 1101 1111
 -define(NEG_BIG_INT  , 2#11101111). %% 1110 1111 | RLP encoded (integer - 64)
@@ -193,6 +194,9 @@ serialize(Map) when ?IS_FATE_MAP(Map) ->
     <<?MAP,
       (rlp_encode_int(Size))/binary,
       (Elements)/binary>>;
+serialize(?FATE_STORE_MAP(Cache, Id)) when Cache =:= #{} ->
+    %% We should never get to serialization without having flushed the caches.
+    <<?MAP_ID, (rlp_encode_int(Id))/binary>>;
 serialize(?FATE_VARIANT(Arities, Tag, Values)) ->
     Arities = [A || A <- Arities, is_integer(A), A < 256],
     Size = length(Arities),
@@ -426,6 +430,9 @@ deserialize2(<<?MAP, Rest/binary>>) ->
         false ->
             error({unknown_map_serialization_format, KVList})
     end;
+deserialize2(<<?MAP_ID, Rest/binary>>) ->
+    {Id, Rest1} = rlp_decode_int(Rest),
+    {?FATE_STORE_MAP(#{}, Id), Rest1};
 deserialize2(<<?VARIANT, Rest/binary>>) ->
     {AritiesBin, <<Tag:8, Rest2/binary>>} = aeser_rlp:decode_one(Rest),
     Arities = binary_to_list(AritiesBin),