diff --git a/.ci/build.sh b/.ci/build.sh
new file mode 100755
index 00000000..999f60c9
--- /dev/null
+++ b/.ci/build.sh
@@ -0,0 +1,13 @@
+#!/bin/bash
+
+set -ex
+
+cargo build --verbose
+cargo test --verbose
+
+if [ "$TRAVIS_RUST_VERSION" = "nightly" ]
+then
+    cargo build --verbose --features no_stdlib
+    cargo test --verbose --features no_stdlib
+fi
+
diff --git a/.travis.yml b/.travis.yml
index 8c91a741..80702bdc 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -6,3 +6,5 @@ rust:
 matrix:
   allow_failures:
     - rust: nightly
+
+script: bash ./.ci/build.sh
\ No newline at end of file
diff --git a/Cargo.toml b/Cargo.toml
index 308685bf..f495d608 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -15,14 +15,34 @@ include = [
 ]
 
 [dependencies]
-num-traits = "*"
+num-traits = "0.2.11"
+
+[dependencies.libm]
+version = "0.2.1"
+optional = true
+
+[dependencies.core-error]
+version = "0.0.1-rc4"
+features = ["alloc"]
+optional = true
+
+[dependencies.hashbrown]
+version = "0.7.1"
+default-features = false
+features = ["ahash", "nightly", "inline-more"]
+optional = true
+
+[dependencies.ahash]
+version = "0.3.2"
+default-features = false
+optional = true
 
 [features]
 #default = ["no_function", "no_index", "no_float", "only_i32", "no_stdlib", "unchecked", "no_optimize"]
 default = [ "optimize_full" ]
 debug_msgs = []     # print debug messages on function registrations and calls
 unchecked = []      # unchecked arithmetic
-no_stdlib = []      # no standard library of utility functions
+no_stdlib = ["num-traits/libm", "hashbrown", "core-error", "libm"]      # no standard library of utility functions
 no_index = []       # no arrays and indexing
 no_float = []       # no floating-point
 no_function = []    # no script-defined functions
diff --git a/src/any.rs b/src/any.rs
index 96fe099b..927f2124 100644
--- a/src/any.rs
+++ b/src/any.rs
@@ -1,7 +1,8 @@
 //! Helper module which defines the `Any` trait to to allow dynamic value handling.
 
-use std::{
-    any::{type_name, TypeId},
+use crate::stdlib::{
+    any::{self, type_name, TypeId},
+    boxed::Box,
     fmt,
 };
 
@@ -12,7 +13,7 @@ pub type Variant = dyn Any;
 pub type Dynamic = Box<Variant>;
 
 /// A trait covering any type.
-pub trait Any: std::any::Any {
+pub trait Any: any::Any {
     /// Get the `TypeId` of this type.
     fn type_id(&self) -> TypeId;
 
@@ -27,7 +28,7 @@ pub trait Any: std::any::Any {
     fn _closed(&self) -> _Private;
 }
 
-impl<T: Clone + std::any::Any + ?Sized> Any for T {
+impl<T: Clone + any::Any + ?Sized> Any for T {
     fn type_id(&self) -> TypeId {
         TypeId::of::<T>()
     }
diff --git a/src/api.rs b/src/api.rs
index 3c248d5b..172e55d4 100644
--- a/src/api.rs
+++ b/src/api.rs
@@ -12,13 +12,15 @@ use crate::scope::Scope;
 #[cfg(not(feature = "no_optimize"))]
 use crate::optimize::optimize_ast;
 
-use std::{
+use crate::stdlib::{
     any::{type_name, TypeId},
-    fs::File,
-    io::prelude::*,
-    path::PathBuf,
+    boxed::Box,
+    string::{String, ToString},
     sync::Arc,
+    vec::Vec,
 };
+#[cfg(not(feature = "no_stdlib"))]
+use crate::stdlib::{fs::File, io::prelude::*, path::PathBuf};
 
 impl<'e> Engine<'e> {
     pub(crate) fn register_fn_raw(
@@ -115,6 +117,7 @@ impl<'e> Engine<'e> {
         parse(&mut tokens_stream.peekable(), self, scope)
     }
 
+    #[cfg(not(feature = "no_stdlib"))]
     fn read_file(path: PathBuf) -> Result<String, EvalAltResult> {
         let mut f = File::open(path.clone())
             .map_err(|err| EvalAltResult::ErrorReadingScriptFile(path.clone(), err))?;
@@ -127,12 +130,14 @@ impl<'e> Engine<'e> {
     }
 
     /// Compile a file into an AST.
+    #[cfg(not(feature = "no_stdlib"))]
     pub fn compile_file(&self, path: PathBuf) -> Result<AST, EvalAltResult> {
         self.compile_file_with_scope(&Scope::new(), path)
     }
 
     /// Compile a file into an AST using own scope.
     /// The scope is useful for passing constants into the script for optimization.
+    #[cfg(not(feature = "no_stdlib"))]
     pub fn compile_file_with_scope(
         &self,
         scope: &Scope,
@@ -145,11 +150,13 @@ impl<'e> Engine<'e> {
     }
 
     /// Evaluate a file.
+    #[cfg(not(feature = "no_stdlib"))]
     pub fn eval_file<T: Any + Clone>(&mut self, path: PathBuf) -> Result<T, EvalAltResult> {
         Self::read_file(path).and_then(|contents| self.eval::<T>(&contents))
     }
 
     /// Evaluate a file with own scope.
+    #[cfg(not(feature = "no_stdlib"))]
     pub fn eval_file_with_scope<T: Any + Clone>(
         &mut self,
         scope: &mut Scope,
@@ -234,6 +241,7 @@ impl<'e> Engine<'e> {
     ///
     /// Note - if `retain_functions` is set to `true`, functions defined by previous scripts are _retained_
     ///        and not cleared from run to run.
+    #[cfg(not(feature = "no_stdlib"))]
     pub fn consume_file(
         &mut self,
         retain_functions: bool,
@@ -247,6 +255,7 @@ impl<'e> Engine<'e> {
     ///
     /// Note - if `retain_functions` is set to `true`, functions defined by previous scripts are _retained_
     ///        and not cleared from run to run.
+    #[cfg(not(feature = "no_stdlib"))]
     pub fn consume_file_with_scope(
         &mut self,
         scope: &mut Scope,
diff --git a/src/builtin.rs b/src/builtin.rs
index b85cf306..1214c1b0 100644
--- a/src/builtin.rs
+++ b/src/builtin.rs
@@ -17,9 +17,12 @@ use num_traits::{
     CheckedShr, CheckedSub,
 };
 
-use std::{
+use crate::stdlib::{
+    boxed::Box,
     fmt::{Debug, Display},
+    format,
     ops::{Add, BitAnd, BitOr, BitXor, Div, Mul, Neg, Range, Rem, Shl, Shr, Sub},
+    string::{String, ToString},
     {i32, i64, u32},
 };
 
diff --git a/src/call.rs b/src/call.rs
index 2a2822eb..a4dd7c90 100644
--- a/src/call.rs
+++ b/src/call.rs
@@ -1,6 +1,7 @@
 //! Helper module which defines `FnArgs` to make function calling easier.
 
 use crate::any::{Any, Dynamic};
+use crate::stdlib::{string::String, vec, vec::Vec};
 
 #[cfg(not(feature = "no_index"))]
 use crate::engine::Array;
diff --git a/src/engine.rs b/src/engine.rs
index bee73cff..9b239e96 100644
--- a/src/engine.rs
+++ b/src/engine.rs
@@ -11,12 +11,17 @@ use crate::optimize::OptimizationLevel;
 #[cfg(not(feature = "no_index"))]
 use crate::INT;
 
-use std::{
+use crate::stdlib::{
     any::{type_name, TypeId},
     borrow::Cow,
+    boxed::Box,
     collections::HashMap,
+    format,
     iter::once,
+    string::{String, ToString},
     sync::Arc,
+    vec,
+    vec::Vec,
 };
 
 /// An dynamic array of `Dynamic` values.
diff --git a/src/error.rs b/src/error.rs
index a582bcb2..166108c8 100644
--- a/src/error.rs
+++ b/src/error.rs
@@ -1,7 +1,7 @@
 //! Module containing error definitions for the parsing process.
 
 use crate::parser::Position;
-use std::{char, error::Error, fmt};
+use crate::stdlib::{char, error::Error, fmt, string::String};
 
 /// Error when tokenizing the script text.
 #[derive(Debug, Eq, PartialEq, Hash, Clone)]
diff --git a/src/fn_register.rs b/src/fn_register.rs
index 12f15047..d05048a9 100644
--- a/src/fn_register.rs
+++ b/src/fn_register.rs
@@ -4,7 +4,7 @@ use crate::any::{Any, Dynamic};
 use crate::engine::{Engine, FnCallArgs};
 use crate::parser::Position;
 use crate::result::EvalAltResult;
-use std::any::TypeId;
+use crate::stdlib::{any::TypeId, boxed::Box, string::ToString, vec};
 
 /// A trait to register custom functions with the `Engine`.
 ///
diff --git a/src/lib.rs b/src/lib.rs
index ceb34396..1e8aa47c 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -16,7 +16,7 @@
 //!
 //! And the Rust part:
 //!
-//! ```rust,no_run
+//! ```rust,ignore
 //! use rhai::{Engine, EvalAltResult, RegisterFn};
 //!
 //! fn main() -> Result<(), EvalAltResult>
@@ -37,8 +37,12 @@
 //!
 //! [Check out the README on GitHub for more information!](https://github.com/jonathandturner/rhai)
 
+#![cfg_attr(feature = "no_stdlib", no_std)]
 #![allow(non_snake_case)]
 
+#[cfg(feature = "no_stdlib")]
+extern crate alloc;
+
 // needs to be here, because order matters for macros
 macro_rules! debug_println {
     () => (
@@ -61,6 +65,8 @@ macro_rules! debug_println {
     );
 }
 
+#[macro_use]
+mod stdlib;
 mod any;
 mod api;
 mod builtin;
diff --git a/src/optimize.rs b/src/optimize.rs
index 8a75a905..b3e11046 100644
--- a/src/optimize.rs
+++ b/src/optimize.rs
@@ -5,7 +5,11 @@ use crate::engine::{Engine, FnCallArgs, KEYWORD_DEBUG, KEYWORD_DUMP_AST, KEYWORD
 use crate::parser::{map_dynamic_to_expr, Expr, FnDef, Stmt, AST};
 use crate::scope::{Scope, ScopeEntry, VariableType};
 
-use std::sync::Arc;
+use crate::stdlib::{
+    sync::Arc,
+    vec::Vec, string::{String, ToString},
+    boxed::Box, vec,
+};
 
 /// Level of optimization performed
 #[derive(Debug, Eq, PartialEq, Hash, Clone, Copy)]
diff --git a/src/parser.rs b/src/parser.rs
index 366329c3..a66990b6 100644
--- a/src/parser.rs
+++ b/src/parser.rs
@@ -8,9 +8,19 @@ use crate::scope::{Scope, VariableType};
 #[cfg(not(feature = "no_optimize"))]
 use crate::optimize::optimize_ast;
 
-use std::{
-    borrow::Cow, char, cmp::Ordering, fmt, iter::Peekable, str::Chars, str::FromStr, sync::Arc,
-    usize,
+use crate::stdlib::{
+    borrow::Cow,
+    boxed::Box,
+    char,
+    cmp::Ordering,
+    fmt, format,
+    iter::Peekable,
+    str::Chars,
+    str::FromStr,
+    string::{String, ToString},
+    sync::Arc,
+    usize, vec,
+    vec::Vec,
 };
 
 /// The system integer type.
diff --git a/src/result.rs b/src/result.rs
index faa8db7c..12eb9d78 100644
--- a/src/result.rs
+++ b/src/result.rs
@@ -4,7 +4,14 @@ use crate::any::Dynamic;
 use crate::error::ParseError;
 use crate::parser::{Position, INT};
 
-use std::{error::Error, fmt, path::PathBuf};
+use crate::stdlib::{
+    error::Error,
+    fmt,
+    string::{String, ToString},
+};
+
+#[cfg(not(feature = "no_stdlib"))]
+use crate::stdlib::path::PathBuf;
 
 /// Evaluation result.
 ///
@@ -47,6 +54,7 @@ pub enum EvalAltResult {
     /// Wrapped value is the type of the actual result.
     ErrorMismatchOutputType(String, Position),
     /// Error reading from a script file. Wrapped value is the path of the script file.
+    #[cfg(not(feature = "no_stdlib"))]
     ErrorReadingScriptFile(PathBuf, std::io::Error),
     /// Inappropriate member access.
     ErrorDotExpr(String, Position),
@@ -93,6 +101,7 @@ impl EvalAltResult {
             }
             Self::ErrorAssignmentToConstant(_, _) => "Assignment to a constant variable",
             Self::ErrorMismatchOutputType(_, _) => "Output type is incorrect",
+            #[cfg(not(feature = "no_stdlib"))]
             Self::ErrorReadingScriptFile(_, _) => "Cannot read from script file",
             Self::ErrorDotExpr(_, _) => "Malformed dot expression",
             Self::ErrorArithmetic(_, _) => "Arithmetic error",
@@ -127,6 +136,7 @@ impl fmt::Display for EvalAltResult {
             }
             Self::LoopBreak => write!(f, "{}", desc),
             Self::Return(_, pos) => write!(f, "{} ({})", desc, pos),
+            #[cfg(not(feature = "no_stdlib"))]
             Self::ErrorReadingScriptFile(path, err) => {
                 write!(f, "{} '{}': {}", desc, path.display(), err)
             }
@@ -199,7 +209,9 @@ impl<T: AsRef<str>> From<T> for EvalAltResult {
 impl EvalAltResult {
     pub fn position(&self) -> Position {
         match self {
-            Self::ErrorReadingScriptFile(_, _) | Self::LoopBreak => Position::none(),
+            #[cfg(not(feature = "no_stdlib"))]
+            Self::ErrorReadingScriptFile(_, _) => Position::none(),
+            Self::LoopBreak => Position::none(),
 
             Self::ErrorParsing(err) => err.position(),
 
@@ -226,7 +238,9 @@ impl EvalAltResult {
 
     pub(crate) fn set_position(&mut self, new_position: Position) {
         match self {
-            Self::ErrorReadingScriptFile(_, _) | Self::LoopBreak => (),
+            #[cfg(not(feature = "no_stdlib"))]
+            Self::ErrorReadingScriptFile(_, _) => (),
+            Self::LoopBreak => (),
 
             Self::ErrorParsing(ParseError(_, ref mut pos))
             | Self::ErrorFunctionNotFound(_, ref mut pos)
diff --git a/src/scope.rs b/src/scope.rs
index 92c1fe14..e1bedde6 100644
--- a/src/scope.rs
+++ b/src/scope.rs
@@ -3,7 +3,12 @@
 use crate::any::{Any, Dynamic};
 use crate::parser::{map_dynamic_to_expr, Expr, Position};
 
-use std::borrow::Cow;
+use crate::stdlib::{
+    borrow::Cow,
+    iter,
+    string::{String, ToString},
+    vec::Vec,
+};
 
 /// Type of a variable in the Scope.
 #[derive(Debug, Eq, PartialEq, Hash, Copy, Clone)]
@@ -193,7 +198,7 @@ impl<'a> Scope<'a> {
     }
 }
 
-impl<'a, K> std::iter::Extend<(K, VariableType, Dynamic)> for Scope<'a>
+impl<'a, K> iter::Extend<(K, VariableType, Dynamic)> for Scope<'a>
 where
     K: Into<Cow<'a, str>>,
 {
diff --git a/src/stdlib.rs b/src/stdlib.rs
new file mode 100644
index 00000000..fa147c7d
--- /dev/null
+++ b/src/stdlib.rs
@@ -0,0 +1,23 @@
+#[cfg(feature = "no_stdlib")]
+mod inner {
+    pub use core::{
+        any, arch, array, ascii, cell, char, clone, cmp, convert, default, f32, f64, ffi, fmt,
+        future, hash, hint, i128, i16, i32, i64, i8, isize, iter, marker, mem, num, ops, option,
+        panic, pin, prelude, ptr, result, slice, str, task, time, u128, u16, u32, u64, u8, usize,
+    };
+
+    pub use alloc::{borrow, boxed, format, string, sync, vec};
+
+    pub use core_error as error;
+
+    pub mod collections {
+        pub use hashbrown::HashMap;
+    }
+}
+
+#[cfg(not(feature = "no_stdlib"))]
+mod inner {
+    pub use std::*;
+}
+
+pub use self::inner::*;