diff --git a/src/machi_cr_client.erl b/src/machi_cr_client.erl
index b104b76..bbb2bbc 100644
--- a/src/machi_cr_client.erl
+++ b/src/machi_cr_client.erl
@@ -295,6 +295,8 @@ do_append_head2(Prefix, Chunk, ChunkExtra, Depth, STime,
             %% io:format(user, "append ~w,", [HeadFLU]),
             do_append_midtail(RestFLUs, Prefix, File, Offset, Chunk, ChunkExtra,
                               [HeadFLU], 0, STime, S);
+        {error, bad_checksum}=BadCS ->
+            {reply, BadCS, S};
         {error, Retry}
           when Retry == partition; Retry == bad_epoch; Retry == wedged ->
             do_append_head(Prefix, Chunk, ChunkExtra, Depth, STime, S);
@@ -359,6 +361,9 @@ do_append_midtail2([FLU|RestFLUs]=FLUs, Prefix, File, Offset, Chunk,
             %% io:format(user, "write ~w,", [FLU]),
             do_append_midtail2(RestFLUs, Prefix, File, Offset, Chunk,
                                ChunkExtra, [FLU|Ws], Depth, STime, S);
+        {error, bad_checksum}=BadCS ->
+            %% TODO: alternate strategy?
+            {reply, BadCS, S};
         {error, Retry}
           when Retry == partition; Retry == bad_epoch; Retry == wedged ->
             do_append_midtail(FLUs, Prefix, File, Offset, Chunk,
@@ -407,6 +412,9 @@ do_read_chunk2(File, Offset, Size, Depth, STime,
                   got, byte_size(BadChunk)});
         {error, partial_read}=Err ->
             {reply, Err, S};
+        {error, bad_checksum}=BadCS ->
+            %% TODO: alternate strategy?
+            {reply, BadCS, S};
         {error, Retry}
           when Retry == partition; Retry == bad_epoch; Retry == wedged ->
             do_read_chunk(File, Offset, Size, Depth, STime, S);
@@ -461,6 +469,9 @@ read_repair2(cp_mode=ConsistencyMode,
         {ok, BadChunk} ->
             exit({todo, bad_chunk_size, ?MODULE, ?LINE, File, Offset,
                   Size, got, byte_size(BadChunk)});
+        {error, bad_checksum}=BadCS ->
+            %% TODO: alternate strategy?
+            {reply, BadCS, S};
         {error, Retry}
           when Retry == partition; Retry == bad_epoch; Retry == wedged ->
             read_repair(ConsistencyMode, ReturnMode, File, Offset,
@@ -482,6 +493,9 @@ read_repair2(ap_mode=ConsistencyMode,
         {ok, BadChunk} ->
             exit({todo, bad_chunk_size, ?MODULE, ?LINE, File,
                   Offset, Size, got, byte_size(BadChunk)});
+        {error, bad_checksum}=BadCS ->
+            %% TODO: alternate strategy?
+            {reply, BadCS, S};
         {error, Retry}
           when Retry == partition; Retry == bad_epoch; Retry == wedged ->
             read_repair(ConsistencyMode, ReturnMode, File,
@@ -537,6 +551,9 @@ read_repair4([First|Rest]=ToRepair, ReturnMode, Chunk, Repaired, File, Offset,
         ok ->
             read_repair4(Rest, ReturnMode, Chunk, [First|Repaired], File,
                          Offset, Size, Depth, STime, S);
+        {error, bad_checksum}=BadCS ->
+            %% TODO: alternate strategy?
+            {reply, BadCS, S};
         {error, Retry}
           when Retry == partition; Retry == bad_epoch; Retry == wedged ->
             read_repair3(ToRepair, ReturnMode, Chunk, Repaired, File,
diff --git a/test/machi_cr_client_test.erl b/test/machi_cr_client_test.erl
index 834da91..d014ff4 100644
--- a/test/machi_cr_client_test.erl
+++ b/test/machi_cr_client_test.erl
@@ -86,6 +86,9 @@ smoke_test() ->
         machi_cr_client:append_chunk(C1, Prefix, Chunk1),
         {ok, {Off1,Size1,File1}} =
             machi_cr_client:append_chunk(C1, Prefix, Chunk1),
+        Chunk1_badcs = {<<?CSUM_TAG_CLIENT_GEN:8, 0:(8*20)>>, Chunk1},
+        {error, bad_checksum} =
+            machi_cr_client:append_chunk(C1, Prefix, Chunk1_badcs),
         {ok, Chunk1} = machi_cr_client:read_chunk(C1, File1, Off1, Size1),
         {ok, PPP} = machi_flu1_client:read_latest_projection(Host, PortBase+0,
                                                              private),
diff --git a/test/machi_proxy_flu1_client_test.erl b/test/machi_proxy_flu1_client_test.erl
index 5b723fe..ac64a22 100644
--- a/test/machi_proxy_flu1_client_test.erl
+++ b/test/machi_proxy_flu1_client_test.erl
@@ -21,6 +21,7 @@
 -module(machi_proxy_flu1_client_test).
 -compile(export_all).
 
+-include("machi.hrl").
 -include("machi_projection.hrl").
 -include_lib("eunit/include/eunit.hrl").
 
@@ -34,6 +35,7 @@ api_smoke_test() ->
     TcpPort = 57124,
     DataDir = "./data.api_smoke_flu",
     W_props = [{initial_wedged, false}],
+    Prefix = <<"prefix">>,
     FLU1 = machi_flu1_test:setup_test_flu(RegName, TcpPort, DataDir,
                                           W_props),
     erase(flu_pid),
@@ -44,15 +46,15 @@ api_smoke_test() ->
         try
             FakeEpoch = ?DUMMY_PV1_EPOCH,
             [{ok, {_,_,_}} = ?MUT:append_chunk(Prox1,
-                                          FakeEpoch, <<"prefix">>, <<"data">>,
+                                          FakeEpoch, Prefix, <<"data">>,
                                           infinity) || _ <- lists:seq(1,5)],
             %% Stop the FLU, what happens?
             machi_flu1:stop(FLU1),
             {error,_} = ?MUT:append_chunk(Prox1,
-                                FakeEpoch, <<"prefix">>, <<"data">>,
+                                FakeEpoch, Prefix, <<"data">>,
                                 infinity),
             {error,partition} = ?MUT:append_chunk(Prox1,
-                                FakeEpoch, <<"prefix">>, <<"data">>,
+                                FakeEpoch, Prefix, <<"data">>,
                                 infinity),
             %% Start the FLU again, we should be able to do stuff immediately
             FLU1b = machi_flu1_test:setup_test_flu(RegName, TcpPort, DataDir,
@@ -60,14 +62,20 @@ api_smoke_test() ->
             put(flu_pid, FLU1b),
             MyChunk = <<"my chunk data">>,
             {ok, {MyOff,MySize,MyFile}} =
-                ?MUT:append_chunk(Prox1, FakeEpoch, <<"prefix">>, MyChunk,
+                ?MUT:append_chunk(Prox1, FakeEpoch, Prefix, MyChunk,
                                   infinity),
             {ok, MyChunk} = ?MUT:read_chunk(Prox1, FakeEpoch, MyFile, MyOff, MySize),
             MyChunk2 = <<"my chunk data, yeah, again">>,
             {ok, {MyOff2,MySize2,MyFile2}} =
-                ?MUT:append_chunk_extra(Prox1, FakeEpoch, <<"prefix">>,
+                ?MUT:append_chunk_extra(Prox1, FakeEpoch, Prefix,
                                         MyChunk2, 4242, infinity),
             {ok, MyChunk2} = ?MUT:read_chunk(Prox1, FakeEpoch, MyFile2, MyOff2, MySize2),
+            MyChunk_badcs = {<<?CSUM_TAG_CLIENT_GEN:8, 0:(8*20)>>, MyChunk},
+            {error, bad_checksum} = ?MUT:append_chunk(Prox1, FakeEpoch,
+                                                      Prefix, MyChunk_badcs),
+            {error, bad_checksum} = ?MUT:write_chunk(Prox1, FakeEpoch,
+                                                     <<"foo-file">>, 99832,
+                                                     MyChunk_badcs),
 
             %% Alright, now for the rest of the API, whee
             BadFile = <<"no-such-file">>,