diff --git a/erlang/apps/sim/src/sim_core.erl b/erlang/apps/sim/src/sim_core.erl
index 252363d..3af4f9b 100644
--- a/erlang/apps/sim/src/sim_core.erl
+++ b/erlang/apps/sim/src/sim_core.erl
@@ -240,6 +240,7 @@ dispatch(Core, Mem, IR, EA) ->
     8#206 -> sim_moves:handle_MOVSM(Core, Mem, IR, EA);
     8#207 -> sim_moves:handle_MOVSS(Core, Mem, IR, EA);
     8#210 -> sim_moves:handle_MOVN(Core, Mem, IR, EA);
+    8#211 -> sim_moves:handle_MOVNI(Core, Mem, IR, EA);
     8#250 -> sim_moves:handle_EXCH(Core, Mem, IR, EA);
     _ ->
       PC = (Core#core.pc_section bsl 18) bor Core#core.pc_offset,
diff --git a/erlang/apps/sim/src/sim_moves.erl b/erlang/apps/sim/src/sim_moves.erl
index c7ffacb..aef7796 100644
--- a/erlang/apps/sim/src/sim_moves.erl
+++ b/erlang/apps/sim/src/sim_moves.erl
@@ -30,6 +30,7 @@
         , handle_MOVEM/4
         , handle_MOVES/4
         , handle_MOVN/4
+        , handle_MOVNI/4
         , handle_MOVS/4
         , handle_MOVSI/4
         , handle_MOVSM/4
@@ -175,6 +176,12 @@ handle_MOVN(Core, Mem, IR, EA) ->
                           fun(Core1, Mem1) -> handle_MOVN(Core1, Mem1, IR, EA) end)
   end.
 
+-spec handle_MOVNI(#core{}, sim_mem:mem(), IR :: word(), #ea{})
+      -> {#core{}, sim_mem:mem(), {ok, integer()} | {error, {module(), term()}}}.
+handle_MOVNI(Core, Mem, IR, #ea{offset = E}) ->
+  AC = IR band 8#17,
+  sim_core:next_pc(sim_core:set_ac(Core, AC, (-E) band ((1 bsl 36) - 1)), Mem).
+
 %% Miscellaneous ===============================================================
 
 ea_address(#ea{section = Section, offset = Offset}) ->
diff --git a/erlang/apps/sim/test/sim_moves_tests.erl b/erlang/apps/sim/test/sim_moves_tests.erl
index 3ebb333..9934100 100644
--- a/erlang/apps/sim/test/sim_moves_tests.erl
+++ b/erlang/apps/sim/test/sim_moves_tests.erl
@@ -52,6 +52,7 @@
 -define(OP_MOVSM, 8#206).
 -define(OP_MOVSS, 8#207).
 -define(OP_MOVN, 8#210).
+-define(OP_MOVNI, 8#211).
 -define(OP_EXCH, 8#250).
 
 %% 2.1.1 Exchange Instruction ==================================================
@@ -224,6 +225,15 @@ movn_minint_test() ->
          [ {#ea{section = 1, offset = 1, islocal = false}, 1 bsl 35} % AC1 = 400000,,0
          ]).
 
+movni_test() ->
+  Prog =
+    [ {1, 8#100, ?INSN(?OP_MOVNI, 1, 0, 0, 8#42)}   % 1,,100/ MOVNI 1,42
+    , {1, 8#101, ?INSN_INVALID}                     % 1,,101/ <invalid>
+    ],
+  expect(Prog, [], {1, 8#101}, ?DEFAULT_FLAGS,
+         [ {#ea{section = 1, offset = 1, islocal = false}, (-8#42) band ((1 bsl 36) - 1)} % AC1 = -42
+         ]).
+
 %% Common code to run short sequences ==========================================
 
 expect(Prog, ACs, ExpectedPC, ExpectedFlags, ExpectedEs) ->