diff --git a/.gitignore b/.gitignore
index be69cc69f..11c5b726f 100644
--- a/.gitignore
+++ b/.gitignore
@@ -163,6 +163,7 @@ infer/src/.project
 /infer/dune-workspace
 /infer/src/dune.common
 /infer/src/dune
+/infer/src/opensource/dune
 .merlin
 
 # generated when looking for dead code
diff --git a/infer/src/Makefile b/infer/src/Makefile
index 78601d613..9fdc8b861 100644
--- a/infer/src/Makefile
+++ b/infer/src/Makefile
@@ -76,7 +76,7 @@ GENERATED_FROM_AUTOCONF = dune.common ../dune-workspace base/Version.ml
 .PHONY: dune-workspace
 dune-workspace: ../dune-workspace
 
-GENERATED_DUNES += dune
+GENERATED_DUNES += dune opensource/dune
 
 SRC_BUILD_COMMON = $(GENERATED_FROM_AUTOCONF) $(GENERATED_DUNES) $(OCAML_SOURCES)
 ifeq ($(BUILD_C_ANALYZERS),yes)
@@ -243,6 +243,7 @@ $(GENERATED_DUNES): dune.common
 
 dune: dune.in
 deadcode/dune: deadcode/dune.in
+opensource/dune: opensource/dune.in
 
 .PHONY: clean
 clean:
diff --git a/infer/src/scuba/LogEntry.ml b/infer/src/base/LogEntry.ml
similarity index 100%
rename from infer/src/scuba/LogEntry.ml
rename to infer/src/base/LogEntry.ml
diff --git a/infer/src/scuba/LogEntry.mli b/infer/src/base/LogEntry.mli
similarity index 100%
rename from infer/src/scuba/LogEntry.mli
rename to infer/src/base/LogEntry.mli
diff --git a/infer/src/scuba/Scuba.ml b/infer/src/base/Scuba.ml
similarity index 100%
rename from infer/src/scuba/Scuba.ml
rename to infer/src/base/Scuba.ml
diff --git a/infer/src/scuba/Scuba.mli b/infer/src/base/Scuba.mli
similarity index 100%
rename from infer/src/scuba/Scuba.mli
rename to infer/src/base/Scuba.mli
diff --git a/infer/src/scuba/ScubaLogging.ml b/infer/src/base/ScubaLogging.ml
similarity index 100%
rename from infer/src/scuba/ScubaLogging.ml
rename to infer/src/base/ScubaLogging.ml
diff --git a/infer/src/scuba/ScubaLogging.mli b/infer/src/base/ScubaLogging.mli
similarity index 100%
rename from infer/src/scuba/ScubaLogging.mli
rename to infer/src/base/ScubaLogging.mli
diff --git a/infer/src/base/dune b/infer/src/base/dune
index 1300750b0..4906b1231 100644
--- a/infer/src/base/dune
+++ b/infer/src/base/dune
@@ -6,9 +6,8 @@
 (library
  (name InferBase)
  (public_name infer.InferBase)
- (flags
-  (:standard -open Core -open InferStdlib -open IStd -open InferGenerated))
+ (flags (:standard -open Core -open InferStdlib -open IStd -open InferGenerated -open OpenSource))
  (libraries cmdliner core mtime.clock.os parmap re sqlite3 zip InferGenerated
-   InferStdlib)
+   InferStdlib OpenSource)
  (preprocess
   (pps ppx_compare ppx_enumerate)))
diff --git a/infer/src/dune.in b/infer/src/dune.in
index 0ae9f503b..76bad75c3 100644
--- a/infer/src/dune.in
+++ b/infer/src/dune.in
@@ -10,27 +10,24 @@
 let ( ^/ ) = Filename.concat
 
 let source_dirs =
-  (if facebook then "facebook" else "opensource")
-  :: ( ( if clang then ["al"; "clang"; "unit" ^/ "clang"]
-       else ["clang_stubs"; "unit" ^/ "clang_stubs"] )
-     @ [ (if java then "java" else "java_stubs")
-       ; "absint"
-       ; "backend"
-       ; "biabduction"
-       ; "bufferoverrun"
-       ; "checkers"
-       ; "concurrency"
-       ; "cost"
-       ; "integration"
-       ; "labs"
-       ; "nullsafe"
-       ; "pulse"
-       ; "quandary"
-       ; "scuba"
-       ; "test_determinator"
-       ; "topl"
-       ; "unit"
-       ; "unit" ^/ "nullsafe" ] )
+  (if clang then ["al"; "clang"; "unit" ^/ "clang"] else ["clang_stubs"; "unit" ^/ "clang_stubs"])
+  @ [ (if java then "java" else "java_stubs")
+    ; "absint"
+    ; "backend"
+    ; "biabduction"
+    ; "bufferoverrun"
+    ; "checkers"
+    ; "concurrency"
+    ; "cost"
+    ; "integration"
+    ; "labs"
+    ; "nullsafe"
+    ; "pulse"
+    ; "quandary"
+    ; "test_determinator"
+    ; "topl"
+    ; "unit"
+    ; "unit" ^/ "nullsafe" ]
 
 
 let infer_binaries = ["infer"; "inferunit"] @ if facebook then ["InferCreateTraceViewLinks"] else []
@@ -60,6 +57,8 @@ let infer_cflags =
   [ "-open"
   ; "Core"
   ; "-open"
+  ; "OpenSource"
+  ; "-open"
   ; "InferStdlib"
   ; "-open"
   ; "IStd"
diff --git a/infer/src/opensource/FbCostModels.ml b/infer/src/opensource/FbCostModels.ml
index eb60fb8f0..062f398db 100644
--- a/infer/src/opensource/FbCostModels.ml
+++ b/infer/src/opensource/FbCostModels.ml
@@ -5,8 +5,6 @@
  * LICENSE file in the root directory of this source tree.
  *)
 
-open! IStd
-
 module Call = struct
-  let dispatch = ProcnameDispatcher.Call.make_dispatcher []
+  let dispatch _ _ _ = None
 end
diff --git a/infer/src/opensource/FbCostModels.mli b/infer/src/opensource/FbCostModels.mli
index 984656839..b28a7b603 100644
--- a/infer/src/opensource/FbCostModels.mli
+++ b/infer/src/opensource/FbCostModels.mli
@@ -5,8 +5,6 @@
  * LICENSE file in the root directory of this source tree.
  *)
 
-open! IStd
-
 module Call : sig
-  val dispatch : (Tenv.t, CostUtils.model, unit) ProcnameDispatcher.Call.dispatcher
+  val dispatch : 'context -> 'procname_t -> 'arg_payload_FuncArg_t_list -> 'f option
 end
diff --git a/infer/src/opensource/FbPatternMatch.ml b/infer/src/opensource/FbPatternMatch.ml
index 97877ab14..fa707a079 100644
--- a/infer/src/opensource/FbPatternMatch.ml
+++ b/infer/src/opensource/FbPatternMatch.ml
@@ -5,6 +5,4 @@
  * LICENSE file in the root directory of this source tree.
  *)
 
-open! IStd
-
 let is_subtype_of_fb_service_handler _tenv _name = false
diff --git a/infer/src/opensource/FbPatternMatch.mli b/infer/src/opensource/FbPatternMatch.mli
index 57a64a192..60d99bece 100644
--- a/infer/src/opensource/FbPatternMatch.mli
+++ b/infer/src/opensource/FbPatternMatch.mli
@@ -5,6 +5,4 @@
  * LICENSE file in the root directory of this source tree.
  *)
 
-open! IStd
-
-val is_subtype_of_fb_service_handler : Tenv.t -> Typ.Name.t -> bool
+val is_subtype_of_fb_service_handler : 'tenv_t -> 'typ_Name_t -> bool
diff --git a/infer/src/opensource/FbThreadSafety.ml b/infer/src/opensource/FbThreadSafety.ml
index 62c07e3db..7e5e7af10 100644
--- a/infer/src/opensource/FbThreadSafety.ml
+++ b/infer/src/opensource/FbThreadSafety.ml
@@ -5,8 +5,6 @@
  * LICENSE file in the root directory of this source tree.
  *)
 
-open! IStd
-
 let is_custom_init _ _ = false
 
 let is_logging_method _ = false
diff --git a/infer/src/opensource/FbThreadSafety.mli b/infer/src/opensource/FbThreadSafety.mli
index eda2a2650..cf35766ec 100644
--- a/infer/src/opensource/FbThreadSafety.mli
+++ b/infer/src/opensource/FbThreadSafety.mli
@@ -5,12 +5,10 @@
  * LICENSE file in the root directory of this source tree.
  *)
 
-open! IStd
+val is_custom_init : 'tenv_t -> 'procname_t -> bool
 
-val is_custom_init : Tenv.t -> Procname.t -> bool
+val is_logging_method : 'procname_t -> bool
 
-val is_logging_method : Procname.t -> bool
-
-val get_fbthreadsafe_class_annot : Procname.t -> Tenv.t -> (string * string) option
+val get_fbthreadsafe_class_annot : 'procname_t -> 'tenv_t -> (string * string) option
 
 val message_fbthreadsafe_class : string -> string -> string
diff --git a/infer/src/opensource/Scribe.ml b/infer/src/opensource/Scribe.ml
index 63bec68a8..59aeee6ff 100644
--- a/infer/src/opensource/Scribe.ml
+++ b/infer/src/opensource/Scribe.ml
@@ -5,8 +5,6 @@
  * LICENSE file in the root directory of this source tree.
  *)
 
-open! IStd
-
 type category = InferEvents
 
 let log _ _ = ()
diff --git a/infer/src/opensource/Scribe.mli b/infer/src/opensource/Scribe.mli
index fbea98fac..a423f5f57 100644
--- a/infer/src/opensource/Scribe.mli
+++ b/infer/src/opensource/Scribe.mli
@@ -5,8 +5,6 @@
  * LICENSE file in the root directory of this source tree.
  *)
 
-open! IStd
-
 type category = InferEvents
 
 val log : category -> string list -> unit
diff --git a/infer/src/opensource/dune.in b/infer/src/opensource/dune.in
new file mode 100644
index 000000000..ea66ff1bc
--- /dev/null
+++ b/infer/src/opensource/dune.in
@@ -0,0 +1,21 @@
+(* -*- tuareg -*- *)
+(*
+ * 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.
+ *)
+(* NOTE: prepend dune.common to this file! *)
+
+(* include the open-source modules only in open-source build modes, otherwise this library is empty *)
+
+;;
+Jbuild_plugin.V1.send
+  (Format.sprintf {|
+(library
+ (name OpenSource)
+ (public_name infer.OpenSource)
+  %s
+)
+|}
+     (if facebook then "(modules)" else "(modules :standard)"))