diff --git a/infer/src/backend/Summary.ml b/infer/src/backend/Summary.ml
index fe0cdd335..a9f7e23d5 100644
--- a/infer/src/backend/Summary.ml
+++ b/infer/src/backend/Summary.ml
@@ -165,10 +165,6 @@ module OnDisk = struct
 
   (** Load procedure summary for the given procedure name and update spec table *)
   let load_summary_to_spec_table =
-    let load_summary_ziplibs zip_specs_filename =
-      let zip_specs_path = Filename.concat Config.specs_dir_name zip_specs_filename in
-      ZipLib.load summary_serializer zip_specs_path
-    in
     let or_from f_load f_filenames proc_name summ_opt =
       match summ_opt with Some _ -> summ_opt | None -> f_load (f_filenames proc_name)
     in
@@ -176,7 +172,6 @@ module OnDisk = struct
       let summ_opt =
         load_from_file (specs_filename_of_procname proc_name)
         |> or_from load_biabduction_model Fn.id proc_name
-        |> or_from load_summary_ziplibs specs_filename proc_name
       in
       Option.iter ~f:(add proc_name) summ_opt ;
       summ_opt
diff --git a/infer/src/base/Config.ml b/infer/src/base/Config.ml
index 909f24b64..d8f6933ad 100644
--- a/infer/src/base/Config.ml
+++ b/infer/src/base/Config.ml
@@ -124,8 +124,6 @@ let costs_report_json = "costs-report.json"
 
 let default_failure_name = "ASSERTION_FAILURE"
 
-let default_in_zip_results_dir = "infer"
-
 (** Dotty output filename **)
 let dotty_frontend_output = "proc_cfgs_frontend.dot"
 
diff --git a/infer/src/base/Config.mli b/infer/src/base/Config.mli
index 58c72cb3f..ccad9c33c 100644
--- a/infer/src/base/Config.mli
+++ b/infer/src/base/Config.mli
@@ -73,8 +73,6 @@ val costs_report_json : string
 
 val default_failure_name : string
 
-val default_in_zip_results_dir : string
-
 val dotty_frontend_output : string
 
 val duplicates_filename : string
diff --git a/infer/src/base/Serialization.ml b/infer/src/base/Serialization.ml
index 451de9537..3b797ed20 100644
--- a/infer/src/base/Serialization.ml
+++ b/infer/src/base/Serialization.ml
@@ -11,9 +11,7 @@ module L = Logging
 
 (** Generic serializer *)
 type 'a serializer =
-  { read_from_string: string -> 'a option
-  ; read_from_file: DB.filename -> 'a option
-  ; write_to_file: data:'a -> DB.filename -> unit }
+  {read_from_file: DB.filename -> 'a option; write_to_file: data:'a -> DB.filename -> unit}
 
 module Key = struct
   type t =
@@ -49,9 +47,6 @@ let create_serializer (key : Key.t) : 'a serializer =
       None )
     else Some value
   in
-  let read_from_string (str : string) : 'a option =
-    read_data (Marshal.from_string str 0) "string"
-  in
   let read_from_file (fname : DB.filename) : 'a option =
     (* The serialization is based on atomic file renames,
        so the deserialization cannot read a file while it is being written. *)
@@ -73,10 +68,8 @@ let create_serializer (key : Key.t) : 'a serializer =
         Marshal.to_channel outc (key.key, version, data) [] ) ;
     PerfEvent.(log (fun logger -> log_end_event logger ()))
   in
-  {read_from_string; read_from_file; write_to_file}
-
+  {read_from_file; write_to_file}
 
-let read_from_string s = s.read_from_string
 
 let read_from_file s = s.read_from_file
 
@@ -88,4 +81,4 @@ let generate_keys () =
   Random.self_init () ;
   let max_rand_int = 0x3FFFFFFF (* determined by Rand library *) in
   let gen () = Random.int max_rand_int in
-  (gen (), gen (), gen (), gen (), gen ())
+  (gen (), gen (), gen ())
diff --git a/infer/src/base/Serialization.mli b/infer/src/base/Serialization.mli
index f30379cf5..b97376398 100644
--- a/infer/src/base/Serialization.mli
+++ b/infer/src/base/Serialization.mli
@@ -33,12 +33,9 @@ val create_serializer : Key.t -> 'a serializer
 val read_from_file : 'a serializer -> DB.filename -> 'a option
 (** Deserialize a file and check the keys *)
 
-val read_from_string : 'a serializer -> string -> 'a option
-(** Deserialize a string and check the keys *)
-
 val write_to_file : 'a serializer -> data:'a -> DB.filename -> unit
 (** Serialize into a file writing value *)
 
-val generate_keys : unit -> int * int * int * int * int
+val generate_keys : unit -> int * int * int
   [@@warning "-32"]
 (** Generate new (random) serialization keys, to be used in an ocaml toplevel *)
diff --git a/infer/src/base/ZipLib.ml b/infer/src/base/ZipLib.ml
deleted file mode 100644
index fbf9ba52d..000000000
--- a/infer/src/base/ZipLib.ml
+++ /dev/null
@@ -1,48 +0,0 @@
-(*
- * Copyright (c) Facebook, Inc. and its affiliates.
- *
- * This source code is licensed under the MIT license found in the
- * LICENSE file in the root directory of this source tree.
- *)
-
-open! IStd
-open PolyVariantEqual
-
-type zip_library = {zip_filename: string; zip_channel: Zip.in_file Lazy.t}
-
-let load_from_zip serializer zip_path zip_library =
-  let (lazy zip_channel) = zip_library.zip_channel in
-  let deserialize = Serialization.read_from_string serializer in
-  match deserialize (Zip.read_entry zip_channel (Zip.find_entry zip_channel zip_path)) with
-  | Some data ->
-      Some data
-  | None ->
-      None
-  | exception Caml.Not_found ->
-      None
-
-
-let load_data serializer path zip_library =
-  let zip_path = Filename.concat Config.default_in_zip_results_dir path in
-  load_from_zip serializer zip_path zip_library
-
-
-(** list of the zip files to search for specs files *)
-let zip_libraries =
-  (* delay until load is called, to avoid stating/opening files at init time *)
-  lazy
-    (let mk_zip_lib zip_filename = {zip_filename; zip_channel= lazy (Zip.open_in zip_filename)} in
-     if
-       Config.is_checker_enabled Biabduction
-       && (not Config.biabduction_models_mode)
-       && Sys.file_exists Config.biabduction_models_jar = `Yes
-     then Some (mk_zip_lib Config.biabduction_models_jar)
-     else None )
-
-
-let load serializer path =
-  (* NOTE: This and [zib_libraries] used to also work with a list of where to find "zip libraries"
-     but now this only handles at most one such library: the biabduction models. There's a chance
-     that this code looks weirder than it should as a result. *)
-  Option.bind (Lazy.force zip_libraries) ~f:(fun zip_library ->
-      load_data serializer path zip_library )
diff --git a/infer/src/base/ZipLib.mli b/infer/src/base/ZipLib.mli
deleted file mode 100644
index 10fc420e5..000000000
--- a/infer/src/base/ZipLib.mli
+++ /dev/null
@@ -1,13 +0,0 @@
-(*
- * Copyright (c) Facebook, Inc. and its affiliates.
- *
- * This source code is licensed under the MIT license found in the
- * LICENSE file in the root directory of this source tree.
- *)
-
-open! IStd
-
-val load : 'a Serialization.serializer -> string -> 'a option
-(** [load serializer path] searches for the file at the given path in the zip libraries. If
-    Config.infer_cache is set, already deserialized data will be saved there and [path] will be
-    searched from the cache first. *)