diff --git a/sledge/Makefile b/sledge/Makefile
index a51ff4493..552a007d1 100644
--- a/sledge/Makefile
+++ b/sledge/Makefile
@@ -91,7 +91,7 @@ clean:
 
 .PHONY: fmt
 fmt:
-	dune build $(FMTS) --auto-promote
+	dune build @fmt --auto-promote
 	ocamlformat -i $(DUNEINS)
 	clang-format -i model/llair_intrinsics.h model/cxxabi.cpp
 	${MAKE} -C test fmt
diff --git a/sledge/dune b/sledge/dune
index 6535e144c..d2d76d948 100644
--- a/sledge/dune
+++ b/sledge/dune
@@ -3,12 +3,13 @@
 ; This source code is licensed under the MIT license found in the
 ; LICENSE file in the root directory of this source tree.
 
-(ignored_subdirs (llvm test))
+(dirs :standard \ llvm test)
 
 (rule
  (targets sledge-help.txt)
  (deps bin/sledge.ml bin/sledge_buck.ml tools/gen_help.sh bin/sledge.exe)
  (action
-  (with-stdout-to sledge-help.txt
+  (with-stdout-to
+   sledge-help.txt
    (run tools/gen_help.sh)))
  (mode promote-until-clean))
diff --git a/sledge/dune-project b/sledge/dune-project
index 54fee445b..929c696e5 100644
--- a/sledge/dune-project
+++ b/sledge/dune-project
@@ -1,2 +1 @@
-(lang dune 1.1)
-(using fmt 1.1)
+(lang dune 2.0)
diff --git a/sledge/dune-workspace b/sledge/dune-workspace
index bfc0b75fd..f250274f4 100644
--- a/sledge/dune-workspace
+++ b/sledge/dune-workspace
@@ -1,4 +1,9 @@
-(lang dune 1.0)
+(lang dune 2.0)
+
+; 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.
 
 (context (opam (switch sledge) (name dbg) (merlin)))
 (context (opam (switch sledge) (name dbg-opt)))
diff --git a/sledge/model/dune b/sledge/model/dune
index fb154b89d..e520fe1b7 100644
--- a/sledge/model/dune
+++ b/sledge/model/dune
@@ -6,17 +6,20 @@
 (rule
  (targets cxxabi.bc)
  (deps cxxabi.cpp Makefile llair_intrinsics.h)
- (action (run make ROOT=../../.. cxxabi.bc)))
+ (action
+  (run make ROOT=../../.. cxxabi.bc)))
 
 (rule
  (targets lib_fuzzer_main.bc)
  (deps lib_fuzzer_main.c Makefile)
- (action (run make ROOT=../../.. lib_fuzzer_main.bc)))
+ (action
+  (run make ROOT=../../.. lib_fuzzer_main.bc)))
 
 (rule
  (targets model.ml)
  (deps cxxabi.bc lib_fuzzer_main.bc)
- (action (run ocaml-crunch -m plain -e bc -o model.ml .)))
+ (action
+  (run ocaml-crunch -m plain -e bc -o model.ml .)))
 
 (library
  (name model)
diff --git a/sledge/ppx_trace.opam b/sledge/ppx_trace.opam
index 5626ba2e2..fec12fd55 100644
--- a/sledge/ppx_trace.opam
+++ b/sledge/ppx_trace.opam
@@ -10,7 +10,7 @@ build: [
 ]
 depends: [
   "ocaml"
-  "dune" {>= "1.11.3" build}
+  "dune" {>= "2.0.0"}
   "ppxlib"
 ]
 synopsis: "Conditionally compiled debug tracing"
diff --git a/sledge/sledge.opam b/sledge/sledge.opam
index 73dd10c35..ecef409ed 100644
--- a/sledge/sledge.opam
+++ b/sledge/sledge.opam
@@ -17,7 +17,7 @@ depends: [
   "crunch" {build}
   "ctypes"
   "ctypes-foreign"
-  "dune" {>= "1.11.3" build}
+  "dune" {>= "2.0" build}
   "dune-build-info"
   "llvm" {= "8.0.0"}
   "ppx_compare"