diff --git a/src/pg.ml b/src/pg.ml
index ee470c43..9d73398f 100644
--- a/src/pg.ml
+++ b/src/pg.ml
@@ -208,6 +208,19 @@ module Caqti_type = struct
       Caqti_type.(
         t9 time time amount amount amount time_span int32 time_span master_sig)
 
+  let aggregate_transfer_fee =
+    let master_sig = Bin_sig.MasterWireFee.caqti in
+    Caqti_type.custom
+      ~encode:(fun
+          AggregateTransferFee.
+            { wire_fee; closing_fee; start_date; end_date; sig_ }
+        -> Ok (wire_fee, closing_fee, start_date, end_date, sig_))
+      ~decode:(fun (wire_fee, closing_fee, start_date, end_date, sig_) ->
+        Ok
+          AggregateTransferFee.
+            { wire_fee; closing_fee; start_date; end_date; sig_ })
+      Caqti_type.(t5 amount amount time time master_sig)
+
   include Caqti_request.Infix
 end
 
@@ -349,31 +362,24 @@ let insert_wire_fee =
     Conn.exec insert_wire_fee
       (wire_method, fee_start, fee_end, wire_fee, closing_fee, master_sig_wire)
 
-(* TODO return type, use AggregateTransferFee.t *)
 let get_wire_fees_by_time =
   let lookup_wire_fee_by_time =
-    Caqti_type.(t3 wire_method time time ->* t2 amount amount)
-      "SELECT (wire_fee).*, (closing_fee).* FROM wire_fee WHERE wire_method=$1 \
-       AND end_date > $2 AND start_date < $3"
+    Caqti_type.(t3 wire_method time time ->* aggregate_transfer_fee)
+      "SELECT (wire_fee).*, (closing_fee).*, start_date, end_date, master_sig \
+       FROM wire_fee WHERE wire_method=$1 AND end_date > $2 AND start_date < \
+       $3"
   in
   fun (module Conn : CONN) ~wire_method ~start_date ~end_date ->
     Conn.collect_list lookup_wire_fee_by_time (wire_method, start_date, end_date)
 
 let get_wire_fees =
   let get_wire_fees =
-    let master_sig = Bin_sig.MasterWireFee.caqti in
-    Caqti_type.(string ->* t5 amount amount time time master_sig)
-      "SELECT wire_fee, closing_fee, start_date, end_date, master_sig FROM \
-       wire_fee WHERE wire_method=$1"
+    Caqti_type.(string ->* aggregate_transfer_fee)
+      "SELECT (wire_fee).*, (closing_fee).*, start_date, end_date, master_sig \
+       FROM wire_fee WHERE wire_method=$1"
   in
   fun (module Conn : CONN) ~wire_method ->
-    let open Syntax in
-    let+ l = Conn.collect_list get_wire_fees wire_method in
-    List.map
-      (fun (wire_fee, closing_fee, start_date, end_date, sig_) ->
-        AggregateTransferFee.
-          { wire_fee; closing_fee; start_date; end_date; sig_ })
-      l
+    Conn.collect_list get_wire_fees wire_method
 
 let get_global_fees =
   let get_global_fees =