diff --git a/src/environ.rs b/src/environ.rs
index e71ea0c..e32828f 100755
--- a/src/environ.rs
+++ b/src/environ.rs
@@ -1,8 +1,10 @@
+use alloc::string::String;
+
+use crate::alloc::string::ToString;
 use crate::parse_list_of_floats;
 use crate::Expr;
 use crate::HashMap;
 use crate::RispError;
-
 macro_rules! ensure_tonicity {
     ($check_fn:expr) => {{
         |args: &[Expr]| -> Result<Expr, RispError> {
diff --git a/src/evaluate.rs b/src/evaluate.rs
index 40cc9aa..9448f82 100755
--- a/src/evaluate.rs
+++ b/src/evaluate.rs
@@ -1,10 +1,15 @@
-use crate::lib::environ::env_get;
-use crate::lib::Environ;
-use crate::lib::Expr;
-use crate::lib::HashMap;
-use crate::lib::RLambda;
-use crate::lib::Rc;
-use crate::lib::RispError;
+use alloc::format;
+use alloc::string::String;
+use alloc::string::ToString;
+use alloc::vec::Vec;
+
+use crate::environ::env_get;
+use crate::Environ;
+use crate::Expr;
+use crate::HashMap;
+use crate::RLambda;
+use crate::Rc;
+use crate::RispError;
 
 pub fn eval(exp: &Expr, env: &mut Environ) -> Result<Expr, RispError> {
     match exp {
diff --git a/src/lib.rs b/src/lib.rs
index eb54c77..3dd2ef2 100755
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -1,12 +1,23 @@
+#![feature(slice_take)]
+#![allow(special_module_name)]
+#![feature(build_hasher_default_const_new)]
+#![no_std]
 use core::fmt;
 
 use core::num::ParseFloatError;
 // use std::hash::DefaultHasher;
 
+use alloc::fmt::format;
+use alloc::rc::Rc;
+use alloc::string::String;
+use alloc::string::ToString;
+use alloc::vec::Vec;
 pub use hashbrown::hash_map::HashMap;
-
-pub use std::io::Write;
-pub use std::rc::Rc;
+pub extern crate alloc;
+use alloc::format;
+use alloc::vec;
+// pub use alloc::;
+// pub use core::rc::Rc;
 
 mod environ;
 pub use environ::default_env;
diff --git a/src/parser.rs b/src/parser.rs
index 975eef1..42a4253 100755
--- a/src/parser.rs
+++ b/src/parser.rs
@@ -1,3 +1,7 @@
+use alloc::string::String;
+use alloc::string::ToString;
+use alloc::vec::Vec;
+
 use crate::evaluate::eval;
 use crate::read_seq;
 use crate::Environ;