diff --git a/.github/workflows/install.yml b/.github/workflows/install.yml
index cac854d85..b41fcc107 100644
--- a/.github/workflows/install.yml
+++ b/.github/workflows/install.yml
@@ -56,7 +56,7 @@ jobs:
           - macOS-latest
           - ubuntu-latest
         ocaml-version:
-          - 4.11.1
+          - 4.12.0
     runs-on: ${{ matrix.os }}
 
     steps:
diff --git a/build-infer.sh b/build-infer.sh
index 25a2afdc2..757d40293 100755
--- a/build-infer.sh
+++ b/build-infer.sh
@@ -17,10 +17,10 @@ DEPENDENCIES_DIR="$INFER_ROOT/facebook/dependencies"
 PLATFORM="$(uname)"
 SANDCASTLE=${SANDCASTLE:-}
 NCPU="$(getconf _NPROCESSORS_ONLN 2>/dev/null || echo 1)"
-INFER_OPAM_DEFAULT_SWITCH="ocaml-variants.4.11.1+flambda"
-INFER_OPAM_DEFAULT_COMPILER="$INFER_OPAM_DEFAULT_SWITCH"
+INFER_OPAM_DEFAULT_SWITCH="4.12.0+flambda"
+INFER_OPAM_DEFAULT_SWITCH_OPTIONS="--package=ocaml-variants.4.12.0+options,ocaml-option-flambda"
 INFER_OPAM_SWITCH=${INFER_OPAM_SWITCH:-$INFER_OPAM_DEFAULT_SWITCH}
-INFER_OPAM_COMPILER=${INFER_OPAM_COMPILER:-$INFER_OPAM_DEFAULT_COMPILER}
+INFER_OPAM_SWITCH_OPTIONS=${INFER_OPAM_SWITCH_OPTIONS:-$INFER_OPAM_DEFAULT_SWITCH_OPTIONS}
 PLUGIN_DIR="$INFER_ROOT/facebook-clang-plugins"
 PLUGIN_SETUP_SCRIPT=${PLUGIN_SETUP_SCRIPT:-setup.sh}
 PLUGIN_SETUP="${PLUGIN_DIR}/clang/${PLUGIN_SETUP_SCRIPT}"
@@ -136,7 +136,7 @@ fi
 
 setup_opam () {
     opam var root 1>/dev/null 2>/dev/null || opam init --reinit --bare --no-setup &&
-    opam_retry opam_switch_create_if_needed "$INFER_OPAM_SWITCH" "$INFER_OPAM_COMPILER" &&
+    opam_retry opam_switch_create_if_needed "$INFER_OPAM_SWITCH" "$INFER_OPAM_SWITCH_OPTIONS" &&
     opam switch set "$INFER_OPAM_SWITCH"
 }
 
diff --git a/infer/tests/build_systems/infertop/toplevel.exp b/infer/tests/build_systems/infertop/toplevel.exp
index 8bef36758..5227f7aba 100644
--- a/infer/tests/build_systems/infertop/toplevel.exp
+++ b/infer/tests/build_systems/infertop/toplevel.exp
@@ -7,8 +7,5 @@ Findlib has been successfully loaded. Additional directives:
   Topfind.reset();;         to force that packages will be reloaded
   #thread;;                 to enable threads
 
-The files [...]/extLib.cma
-and [...]/infertop.bc.exe
-disagree over interface Base64
 n$4
 false
diff --git a/opam/infer.opam b/opam/infer.opam
index ae0ce17fa..59f5152f7 100644
--- a/opam/infer.opam
+++ b/opam/infer.opam
@@ -35,7 +35,7 @@ depends: [
   "memtrace" {>="0.1.2"}
   "mlgmpidl" {>="1.2.12"}
   "mtime"
-  "ocaml" {>="4.09.0"}
+  "ocaml" {>="4.12.0"}
   "ocamlfind" {build}
   "ocamlgraph"
   "ounit" {>="2.0.5"}
diff --git a/opam/infer.opam.locked b/opam/infer.opam.locked
index aead89858..caaa6d9c8 100644
--- a/opam/infer.opam.locked
+++ b/opam/infer.opam.locked
@@ -1,6 +1,6 @@
 opam-version: "2.0"
 name: "infer"
-version: "1.0.0"
+version: "1.1.0"
 synopsis: "A static analyzer for Java, C, C++, and Objective-C"
 maintainer: "the infer team"
 authors: "Facebook"
@@ -27,76 +27,77 @@ depends: [
   "atd" {= "2.2.1"}
   "atdgen" {= "2.2.1"}
   "atdgen-runtime" {= "2.2.1"}
-  "base" {= "v0.14.0"}
+  "base" {= "v0.14.1"}
   "base-bigarray" {= "base"}
   "base-bytes" {= "base"}
   "base-threads" {= "base"}
   "base-unix" {= "base"}
-  "base64" {= "3.4.0"}
+  "base64" {= "3.5.0"}
   "base_bigstring" {= "v0.14.0"}
-  "base_quickcheck" {= "v0.14.0"}
+  "base_quickcheck" {= "v0.14.1"}
+  "bigarray-compat" {= "1.0.0"}
   "bin_prot" {= "v0.14.0"}
   "biniou" {= "1.2.1"}
   "camlidl" {= "1.09"}
   "camlzip" {= "1.10"}
   "cmdliner" {= "1.0.4"}
   "conf-autoconf" {= "0.1"}
-  "conf-gmp" {= "2"}
-  "conf-m4" {= "1"}
+  "conf-gmp" {= "3"}
   "conf-mpfr" {= "2"}
   "conf-perl" {= "1"}
-  "conf-pkg-config" {= "1.3"}
+  "conf-pkg-config" {= "2"}
   "conf-sqlite3" {= "1"}
   "conf-which" {= "1"}
   "conf-zlib" {= "1"}
-  "core" {= "v0.14.0"}
-  "core_kernel" {= "v0.14.0"}
-  "cppo" {= "1.6.6"}
-  "csexp" {= "1.3.1"}
-  "ctypes" {= "0.17.1"}
-  "dune" {= "2.7.1"}
-  "dune-configurator" {= "2.7.1"}
+  "core" {= "v0.14.1"}
+  "core_kernel" {= "v0.14.1"}
+  "cppo" {= "1.6.7"}
+  "csexp" {= "1.5.1"}
+  "ctypes" {= "0.18.0"}
+  "dune" {= "2.8.5"}
+  "dune-configurator" {= "2.8.5"}
   "easy-format" {= "1.3.2"}
-  "extlib" {= "1.7.7"}
+  "extlib" {= "1.7.8"}
   "fieldslib" {= "v0.14.0"}
   "integers" {= "0.4.0"}
   "iter" {= "1.2.1"}
   "jane-street-headers" {= "v0.14.0"}
   "javalib" {= "3.2.1"}
   "jst-config" {= "v0.14.0"}
-  "memtrace" {= "0.1.2"}
-  "menhir" {= "20200624"}
-  "menhirLib" {= "20200624"}
-  "menhirSdk" {= "20200624"}
-  "mlgmpidl" {= "1.2.12"}
+  "memtrace" {= "0.2.1.2"}
+  "menhir" {= "20210419"}
+  "menhirLib" {= "20210419"}
+  "menhirSdk" {= "20210419"}
+  "mlgmpidl" {= "1.2.13"}
   "mtime" {= "1.2.0"}
-  "num" {= "1.3"}
-  "ocaml" {= "4.11.1"}
-  "ocaml-compiler-libs" {= "v0.12.1"}
-  "ocaml-config" {= "1"}
-  "ocaml-migrate-parsetree" {= "1.7.3"}
-  "ocaml-variants" {= "4.11.1+flambda"}
+  "num" {= "1.4"}
+  "ocaml" {= "4.12.0"}
+  "ocaml-compiler-libs" {= "v0.12.3"}
+  "ocaml-config" {= "2"}
+  "ocaml-migrate-parsetree" {= "2.1.0"}
+  "ocaml-option-flambda" {= "1"}
+  "ocaml-variants" {= "4.12.0+options"}
   "ocamlbuild" {= "0.14.0"}
-  "ocamlfind" {= "1.8.1"}
-  "ocamlgraph" {= "1.8.8"}
+  "ocamlfind" {= "1.9.1"}
+  "ocamlgraph" {= "2.0.0"}
   "octavius" {= "1.2.2"}
-  "ounit" {= "2.2.3"}
-  "ounit2" {= "2.2.3"}
-  "parmap" {= "1.1.1"}
+  "ounit" {= "2.2.4"}
+  "ounit2" {= "2.2.4"}
+  "parmap" {= "1.2.3"}
   "parsexp" {= "v0.14.0"}
   "ppx_assert" {= "v0.14.0"}
   "ppx_base" {= "v0.14.0"}
   "ppx_bench" {= "v0.14.1"}
   "ppx_bin_prot" {= "v0.14.0"}
-  "ppx_blob" {= "0.7.0"}
+  "ppx_blob" {= "0.7.2"}
   "ppx_cold" {= "v0.14.0"}
   "ppx_compare" {= "v0.14.0"}
-  "ppx_custom_printf" {= "v0.14.0"}
+  "ppx_custom_printf" {= "v0.14.1"}
   "ppx_derivers" {= "1.2.1"}
-  "ppx_deriving" {= "4.5"}
+  "ppx_deriving" {= "5.2.1"}
   "ppx_enumerate" {= "v0.14.0"}
-  "ppx_expect" {= "v0.14.0"}
-  "ppx_fields_conv" {= "v0.14.1"}
+  "ppx_expect" {= "v0.14.1"}
+  "ppx_fields_conv" {= "v0.14.2"}
   "ppx_fixed_literal" {= "v0.14.0"}
   "ppx_hash" {= "v0.14.0"}
   "ppx_here" {= "v0.14.0"}
@@ -105,21 +106,19 @@ depends: [
   "ppx_js_style" {= "v0.14.0"}
   "ppx_let" {= "v0.14.0"}
   "ppx_module_timer" {= "v0.14.0"}
-  "ppx_optcomp" {= "v0.14.0"}
+  "ppx_optcomp" {= "v0.14.1"}
   "ppx_optional" {= "v0.14.0"}
   "ppx_pipebang" {= "v0.14.0"}
-  "ppx_sexp_conv" {= "v0.14.1"}
-  "ppx_sexp_message" {= "v0.14.0"}
+  "ppx_sexp_conv" {= "v0.14.3"}
+  "ppx_sexp_message" {= "v0.14.1"}
   "ppx_sexp_value" {= "v0.14.0"}
   "ppx_stable" {= "v0.14.1"}
   "ppx_string" {= "v0.14.1"}
-  "ppx_tools" {= "6.2"}
-  "ppx_typerep_conv" {= "v0.14.1"}
+  "ppx_typerep_conv" {= "v0.14.2"}
   "ppx_variants_conv" {= "v0.14.1"}
   "ppx_yojson_conv" {= "v0.14.0"}
   "ppx_yojson_conv_lib" {= "v0.14.0"}
-  "ppxfind" {= "1.4"}
-  "ppxlib" {= "0.15.0"}
+  "ppxlib" {= "0.22.0"}
   "protocol_version_header" {= "v0.14.0"}
   "re" {= "1.9.0"}
   "result" {= "1.5"}
@@ -129,18 +128,18 @@ depends: [
   "sexplib0" {= "v0.14.0"}
   "spawn" {= "v0.13.0"}
   "splittable_random" {= "v0.14.0"}
-  "sqlite3" {= "5.0.2"}
+  "sqlite3" {= "5.0.3"}
   "stdio" {= "v0.14.0"}
-  "stdlib-shims" {= "0.1.0"}
+  "stdlib-shims" {= "0.3.0"}
   "textutils" {= "v0.14.0"}
   "time_now" {= "v0.14.0"}
   "timezone" {= "v0.14.0"}
-  "topkg" {= "1.0.2"}
+  "topkg" {= "1.0.3"}
   "typerep" {= "v0.14.0"}
   "variantslib" {= "v0.14.0"}
   "xmlm" {= "1.3.0"}
   "yojson" {= "1.7.0"}
-  "zarith" {= "1.9.1"}
+  "zarith" {= "1.12"}
 ]
 depexts: [
   [ ["ubuntu"] ["default-jdk"] ]
diff --git a/scripts/opam_utils.sh b/scripts/opam_utils.sh
index b9b11f1a2..7ad2f4055 100644
--- a/scripts/opam_utils.sh
+++ b/scripts/opam_utils.sh
@@ -50,7 +50,7 @@ opam_require_version_2 () {
 # assumes opam is available and initialized
 opam_switch_create_if_needed () {
     local switch=$1
-    local compiler=$2
+    local options=$2
     local switch_exists=no
     for installed_switch in $(opam switch list --short); do
         if [ "$installed_switch" == "$switch" ]; then
@@ -63,7 +63,7 @@ opam_switch_create_if_needed () {
         if [ -n "$opam_root" ]; then
             rm -rf "$opam_root/$switch" || true
         fi
-        opam switch create "$switch" "$compiler"
+        opam switch create "$switch" "$options"
     fi
 }