diff --git a/src/machi_admin_util.erl b/src/machi_admin_util.erl
index 20cfbfe..770a566 100644
--- a/src/machi_admin_util.erl
+++ b/src/machi_admin_util.erl
@@ -95,7 +95,7 @@ verify_file_checksums_common(Sock1, EpochID, File, ReadChunk) ->
     try
         case ?FLU_C:checksum_list(Sock1, EpochID, File) of
             {ok, InfoBin} ->
-                {Info, _} = machi_checksums:split_checksum_list_blob_decode(InfoBin),
+                {Info, _} = machi_csum_table:split_checksum_list_blob_decode(InfoBin),
                 Res = lists:foldl(verify_chunk_checksum(File, ReadChunk),
                                   [], Info),
                 {ok, Res};
diff --git a/src/machi_csum_table.erl b/src/machi_csum_table.erl
index e45dc5e..9720ddc 100644
--- a/src/machi_csum_table.erl
+++ b/src/machi_csum_table.erl
@@ -59,11 +59,12 @@ open(CSumFilename, _Opts) ->
 -spec find(table(), machi_dt:chunk_pos(), machi_dt:chunk_size()) ->
                   {ok, machi_dt:chunk_csum()} | {error, trimmed|notfound}.
 find(#machi_csum_table{table=T}, Offset, Size) ->
+    %% TODO: Check whether all bytes here are written or not
     case ets:lookup(T, Offset) of
         [{Offset, Size, trimmed}] -> {error, trimmed};
         [{Offset, Size, Checksum}] -> {ok, Checksum};
-        [{Offset, _, Checksum}] -> {ok, Checksum};
-        [] -> {error, notfound}
+        [{Offset, _, _}] -> {error, unknown_chunk};
+        [] -> {error, unknown_chunk}
     end.
 
 -spec write(table(), machi_dt:chunk_pos(), machi_dt:chunk_size(),
diff --git a/src/machi_file_proxy.erl b/src/machi_file_proxy.erl
index 40193ee..8a850de 100644
--- a/src/machi_file_proxy.erl
+++ b/src/machi_file_proxy.erl
@@ -597,9 +597,10 @@ handle_write(FHd, CsumTable, Filename, TaggedCsum, Offset, Data, U) ->
             case machi_csum_table:find(CsumTable, Offset, Size) of
                 {error, trimmed} = Error ->
                     Error;
-                {error, notfound} ->
-                    %% Just unknown pair of {offset, size}
-                    %% given. Trust U and return as it is used
+                {error, unknown_chunk} ->
+                    %% The specified has some bytes written, while
+                    %% it's not in the checksum table. Trust U and
+                    %% return as it is used.
                     {error, written};
                 {ok, TaggedCsum} ->
                     case do_read(FHd, Filename, TaggedCsum, Offset, Size) of
diff --git a/test/machi_csum_table_test.erl b/test/machi_csum_table_test.erl
index a9535af..9846e1a 100644
--- a/test/machi_csum_table_test.erl
+++ b/test/machi_csum_table_test.erl
@@ -3,27 +3,29 @@
 
 smoke_test() ->
     Filename = "./temp-checksum-dumb-file",
-    {ok, MC} = machi_checksums:new(Filename),
+    _ = file:delete(Filename),
+    {ok, MC} = machi_csum_table:open(Filename, []),
     {Offset, Size, Checksum} = {64, 34, <<"deadbeef">>},
-    {error, unwritten} = machi_checksums:find(MC, Offset, Size),
-    ok = machi_checksums:write(MC, Offset, Size, Checksum),
-    {ok, Checksum} = machi_checksums:find(MC, Offset, Size),
-    ok = machi_checksums:trim(MC, Offset, Size),
-    {error, trimmed} = machi_checksums:find(MC, Offset, Size),
-    ok = machi_checksums:destroy(MC),
-    ok = machi_checksums:delete_file(MC).
+    {error, unknown_chunk} = machi_csum_table:find(MC, Offset, Size),
+    ok = machi_csum_table:write(MC, Offset, Size, Checksum),
+    {ok, Checksum} = machi_csum_table:find(MC, Offset, Size),
+    ok = machi_csum_table:trim(MC, Offset, Size),
+    {error, trimmed} = machi_csum_table:find(MC, Offset, Size),
+    ok = machi_csum_table:close(MC),
+    ok = machi_csum_table:delete(MC).
 
 close_test() ->
     Filename = "./temp-checksum-dumb-file-2",
-    {ok, MC} = machi_checksums:new(Filename),
+    _ = file:delete(Filename),
+    {ok, MC} = machi_csum_table:open(Filename, []),
     {Offset, Size, Checksum} = {64, 34, <<"deadbeef">>},
-    {error, unwritten} = machi_checksums:find(MC, Offset, Size),
-    ok = machi_checksums:write(MC, Offset, Size, Checksum),
-    {ok, Checksum} = machi_checksums:find(MC, Offset, Size),
-    ok = machi_checksums:destroy(MC),
+    {error, unknown_chunk} = machi_csum_table:find(MC, Offset, Size),
+    ok = machi_csum_table:write(MC, Offset, Size, Checksum),
+    {ok, Checksum} = machi_csum_table:find(MC, Offset, Size),
+    ok = machi_csum_table:close(MC),
 
-    {ok, MC2} = machi_checksums:new(Filename),
-    {ok, Checksum} = machi_checksums:find(MC2, Offset, Size),
-    ok = machi_checksums:trim(MC2, Offset, Size),
-    {error, trimmed} = machi_checksums:find(MC2, Offset, Size),
-    ok = machi_checksums:delete_file(MC2).
+    {ok, MC2} = machi_csum_table:open(Filename, []),
+    {ok, Checksum} = machi_csum_table:find(MC2, Offset, Size),
+    ok = machi_csum_table:trim(MC2, Offset, Size),
+    {error, trimmed} = machi_csum_table:find(MC2, Offset, Size),
+    ok = machi_csum_table:delete(MC2).