diff --git a/src/leveled_bookie.erl b/src/leveled_bookie.erl
index 1333eed..0550436 100644
--- a/src/leveled_bookie.erl
+++ b/src/leveled_bookie.erl
@@ -460,7 +460,7 @@ book_put(Pid, Bucket, Key, Object, IndexSpecs, Tag) ->
                 leveled_codec:index_specs(), 
                 leveled_codec:tag(), infinity|integer()) -> ok|pause.
 
-book_put(Pid, Bucket, Key, Object, IndexSpecs, Tag, TTL) ->
+book_put(Pid, Bucket, Key, Object, IndexSpecs, Tag, TTL) when is_atom(Tag) ->
     gen_server:call(Pid,
                     {put, Bucket, Key, Object, IndexSpecs, Tag, TTL},
                     infinity).
diff --git a/src/leveled_codec.erl b/src/leveled_codec.erl
index f39e38b..b749302 100644
--- a/src/leveled_codec.erl
+++ b/src/leveled_codec.erl
@@ -28,6 +28,7 @@
         to_ledgerkey/5,
         from_ledgerkey/1,
         from_ledgerkey/2,
+        isvalid_ledgerkey/1,
         to_inkerkey/2,
         to_inkerkv/6,
         from_inkerkv/1,
@@ -53,7 +54,7 @@
 -define(NRT_IDX, "$aae.").
 
 -type tag() :: 
-        leveled_head:object_tag()|?IDX_TAG|?HEAD_TAG.
+        leveled_head:object_tag()|?IDX_TAG|?HEAD_TAG|atom().
 -type key() :: 
         binary()|string()|{binary(), binary()}.
         % Keys SHOULD be binary()
@@ -325,6 +326,15 @@ to_ledgerkey(Bucket, {Key, SubKey}, ?HEAD_TAG) ->
 to_ledgerkey(Bucket, Key, Tag) ->
     {Tag, Bucket, Key, null}.
 
+%% No spec - due to tests
+%% @doc
+%% Check that the ledgerkey is a valid format, to handle un-checksummed keys
+%% that may be returned corrupted (such as from the Journal)
+isvalid_ledgerkey({Tag, _B, _K, _SK}) ->
+    is_atom(Tag);
+isvalid_ledgerkey(_LK) ->
+    false.
+
 -spec endkey_passed(ledger_key(), ledger_key()) -> boolean().
 %% @oc
 %% Compare a key against a query key, only comparing elements that are non-null
@@ -370,7 +380,7 @@ get_tagstrategy({Tag, _, _, _}, Strategy) ->
             TagStrat;
         false ->
             leveled_log:log("IC012", [Tag, Strategy]),
-            skip
+            retain
     end.
 
 %%%============================================================================
@@ -713,6 +723,14 @@ next_key({Type, Bucket}) when is_binary(Type), is_binary(Bucket) ->
 
 -ifdef(TEST).
 
+valid_ledgerkey_test() ->
+    UserDefTag = {user_defined, <<"B">>, <<"K">>, null},
+    ?assertMatch(true, isvalid_ledgerkey(UserDefTag)),
+    KeyNotTuple = [?STD_TAG, <<"B">>, <<"K">>, null],
+    ?assertMatch(false, isvalid_ledgerkey(KeyNotTuple)),
+    TagNotAtom = {"tag", <<"B">>, <<"K">>, null},
+    ?assertMatch(false, isvalid_ledgerkey(TagNotAtom)),
+    ?assertMatch(retain, get_tagstrategy(UserDefTag, inker_reload_strategy([]))).
 
 indexspecs_test() ->
     IndexSpecs = [{add, "t1_int", 456},
diff --git a/src/leveled_inker.erl b/src/leveled_inker.erl
index 4b693c9..0a758cf 100644
--- a/src/leveled_inker.erl
+++ b/src/leveled_inker.erl
@@ -357,7 +357,8 @@ ink_loadpcl(Pid, MinSQN, FilterFun, Penciller) ->
 ink_compactjournal(Pid, Bookie, Timeout) ->
     CheckerInitiateFun = fun initiate_penciller_snapshot/1,
     CheckerCloseFun = fun leveled_penciller:pcl_close/1,
-    CheckerFilterFun = fun leveled_penciller:pcl_checksequencenumber/3,
+    CheckerFilterFun =
+        wrap_checkfilterfun(fun leveled_penciller:pcl_checksequencenumber/3),
     gen_server:call(Pid,
                         {compact,
                             Bookie,
@@ -1185,6 +1186,20 @@ initiate_penciller_snapshot(Bookie) ->
     MaxSQN = leveled_penciller:pcl_getstartupsequencenumber(LedgerSnap),
     {LedgerSnap, MaxSQN}.
 
+
+-spec wrap_checkfilterfun(fun()) -> fun().
+%% @doc
+%% Make a check of the validity of the key being passed into the CheckFilterFun
+wrap_checkfilterfun(CheckFilterFun) ->
+    fun(Pcl, LK, SQN) ->
+        case leveled_codec:isvalid_ledgerkey(LK) of
+            true ->
+                CheckFilterFun(Pcl, LK, SQN);
+            false ->
+                false
+        end
+    end.
+
 %%%============================================================================
 %%% Test
 %%%============================================================================
@@ -1438,6 +1453,16 @@ empty_manifest_test() ->
     ink_close(Ink2),
     clean_testdir(RootPath).
 
+
+wrapper_test() ->
+    KeyNotTuple = [?STD_TAG, <<"B">>, <<"K">>, null],
+    TagNotAtom = {"tag", <<"B">>, <<"K">>, null},
+    CheckFilterFun = fun(_Pcl, _LK, _SQN) -> true end,
+    WrappedFun = wrap_checkfilterfun(CheckFilterFun),
+    ?assertMatch(false, WrappedFun(null, KeyNotTuple, 1)),
+    ?assertMatch(false, WrappedFun(null, TagNotAtom, 1)).
+    
+
 coverage_cheat_test() ->
     {noreply, _State0} = handle_info(timeout, #state{}),
     {ok, _State1} = code_change(null, #state{}, null).
diff --git a/src/leveled_penciller.erl b/src/leveled_penciller.erl
index fe30e71..076b198 100644
--- a/src/leveled_penciller.erl
+++ b/src/leveled_penciller.erl
@@ -483,18 +483,10 @@ pcl_fetchnextkey(Pid, StartKey, EndKey, AccFun, InitAcc) ->
 %% If the key is not present, it will be assumed that a higher sequence number
 %% tombstone once existed, and false will be returned.
 pcl_checksequencenumber(Pid, Key, SQN) ->
-    try
-        Hash = leveled_codec:segment_hash(Key),
-        if
-            Hash /= no_lookup ->
-                gen_server:call(Pid, {check_sqn, Key, Hash, SQN}, infinity)
-        end
-    catch
-        % Can't let this crash here, as when journal files are corrupted,
-        % corrupted input might be received by the penciller for this check.
-        % Want to be able to compact away this corruption - not end up with
-        % perpetually failing compaction jobs
-        _Type:_Error -> false
+    Hash = leveled_codec:segment_hash(Key),
+    if
+        Hash /= no_lookup ->
+            gen_server:call(Pid, {check_sqn, Key, Hash, SQN}, infinity)
     end.
 
 -spec pcl_workforclerk(pid()) -> ok.
@@ -2012,16 +2004,6 @@ simple_server_test() ->
                                                     "Key0004",
                                                     null},
                                                 3004)),
-    
-    % Try a busted key - and get false, as the exception should be handled
-    % Mimics a bad ledger key being discovered in the Journal, want to get
-    % false rather than just crashing.  
-    ?assertMatch(false, pcl_checksequencenumber(PclSnap,
-                                                    [o,
-                                                        "Bucket0004",
-                                                        "Key0004",
-                                                        null],
-                                                    3004)),
 
     % Add some more keys and confirm that check sequence number still
     % sees the old version in the previous snapshot, but will see the new