diff --git a/Cargo.toml b/Cargo.toml
index d47f998..1f93c79 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -8,3 +8,6 @@ edition = "2018"
 
 version = "0.3.1"
 authors = ["wycats", "rustasync"]
+
+[dependencies]
+sgx_tstd = { rev = "v1.1.3", git = "https://github.com/apache/teaclave-sgx-sdk.git", features = ["net"] }
\ No newline at end of file
diff --git a/rust-toolchain b/rust-toolchain
new file mode 100644
index 0000000..27df7dc
--- /dev/null
+++ b/rust-toolchain
@@ -0,0 +1 @@
+nightly-2021-05-11
\ No newline at end of file
diff --git a/src/lib.rs b/src/lib.rs
index 0df75b0..27fbce4 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -44,10 +44,21 @@
 #![doc(html_favicon_url = "https://yoshuawuyts.com/assets/http-rs/favicon.ico")]
 #![doc(html_logo_url = "https://yoshuawuyts.com/assets/http-rs/logo-rounded.png")]
 
+
+// ensure we don't import any parts of the std library - we use sgx_tstd instead
+#![no_std]
+#[macro_use]
+extern crate sgx_tstd as std;
+
 use std::cmp::Ordering;
-use std::collections::{btree_map, BTreeMap};
+use std::collections::{btree_map, btree_map::BTreeMap};
 use std::ops::Index;
 
+use std::{
+    vec::Vec,
+    string::{String, ToString}
+};
+
 use crate::nfa::{CharacterClass, NFA};
 
 #[doc(hidden)]
diff --git a/src/nfa.rs b/src/nfa.rs
index 7d6df04..ca578e1 100644
--- a/src/nfa.rs
+++ b/src/nfa.rs
@@ -1,3 +1,9 @@
+use sgx_tstd as std;
+use std::{
+    string::{String, ToString},
+    vec::Vec,
+};
+
 use std::collections::HashSet;
 
 use self::CharacterClass::{Ascii, InvalidChars, ValidChars};