diff --git a/rustler_mix/lib/mix/tasks/compile.rustler.ex b/rustler_mix/lib/mix/tasks/compile.rustler.ex
index 681e63b8..101f8a24 100644
--- a/rustler_mix/lib/mix/tasks/compile.rustler.ex
+++ b/rustler_mix/lib/mix/tasks/compile.rustler.ex
@@ -5,16 +5,20 @@ defmodule Mix.Tasks.Compile.Rustler do
 
   def run(_args) do
     config = Mix.Project.config()
-    crates = Keyword.get(config, :rustler_crates) || raise_missing_crates()
+    case Mix.Project.umbrella?(config) do
+      true -> nil
+      false ->
+        crates = Keyword.get(config, :rustler_crates) || raise_missing_crates()
 
-    File.mkdir_p!(priv_dir())
+        File.mkdir_p!(priv_dir())
 
-    Enum.map(crates, &compile_crate/1)
+        Enum.map(crates, &compile_crate/1)
 
-    # Workaround for a mix problem. We should REALLY get this fixed properly.
-    _ = symlink_or_copy(config,
-      Path.expand("priv"),
-      Path.join(Mix.Project.app_path(config), "priv"))
+        # Workaround for a mix problem. We should REALLY get this fixed properly.
+        _ = symlink_or_copy(config,
+          Path.expand("priv"),
+          Path.join(Mix.Project.app_path(config), "priv"))
+    end
   end
 
 
diff --git a/src/lib.rs b/src/lib.rs
index 4088390d..82953c46 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -43,6 +43,7 @@ mod term;
 
 pub use term::{ NifTerm };
 pub use types::{ NifEncoder, NifDecoder };
+pub use wrapper::nif_interface::ErlNifTaskFlags;
 pub mod resource;
 
 pub mod dynamic;
diff --git a/src/wrapper/nif_interface.rs b/src/wrapper/nif_interface.rs
index 51e0bc09..83a95d13 100644
--- a/src/wrapper/nif_interface.rs
+++ b/src/wrapper/nif_interface.rs
@@ -33,12 +33,12 @@ pub enum NIF_ERROR {
 
 pub type DEF_NIF_FUNC = erlang_nif_sys::ErlNifFunc;
 pub type DEF_NIF_ENTRY = erlang_nif_sys::ErlNifEntry;
-pub use self::erlang_nif_sys::NIF_MAJOR_VERSION;
-pub use self::erlang_nif_sys::NIF_MINOR_VERSION;
-pub use self::erlang_nif_sys::ErlNifResourceFlags as NIF_RESOURCE_FLAGS;
+pub use ::erlang_nif_sys::NIF_MAJOR_VERSION;
+pub use ::erlang_nif_sys::NIF_MINOR_VERSION;
+pub use ::erlang_nif_sys::ErlNifResourceFlags as NIF_RESOURCE_FLAGS;
 
-pub use self::erlang_nif_sys::ErlNifBinaryToTerm as NIF_BINARY_TO_TERM_OPTS;
-pub use self::erlang_nif_sys::ERL_NIF_BIN2TERM_SAFE;
+pub use ::erlang_nif_sys::ErlNifBinaryToTerm as NIF_BINARY_TO_TERM_OPTS;
+pub use ::erlang_nif_sys::ERL_NIF_BIN2TERM_SAFE;
 
 #[repr(C)]
 pub enum ErlNifTaskFlags {
@@ -210,7 +210,7 @@ pub unsafe fn enif_keep_resource(obj: NIF_RESOURCE_HANDLE) {
     erlang_nif_sys::enif_keep_resource(obj)
 }
 
-pub use self::erlang_nif_sys::{
+pub use ::erlang_nif_sys::{
     ErlNifMapIterator,
     ErlNifMapIteratorEntry,
     ErlNifPid,