diff --git a/Cargo.toml b/Cargo.toml
index f614a1d..a2f5405 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -12,7 +12,8 @@ documentation = "https://docs.rs/ipnet"
 edition = "2018"
 
 [features]
-default = []
+default = ["std"]
+std = []
 # Implements "schemars::JsonSchema". Also implies "serde".
 json = ["serde", "schemars"]
 
diff --git a/src/ipext.rs b/src/ipext.rs
index aff7930..15e0fea 100644
--- a/src/ipext.rs
+++ b/src/ipext.rs
@@ -4,9 +4,12 @@
 //! the `Ipv4Addr` and `Ipv6Addr` types with methods to perform these
 //! operations.
 
-use std::cmp::Ordering::{Less, Equal};
-use std::iter::{FusedIterator, DoubleEndedIterator};
-use std::mem;
+use core::cmp::Ordering::{Less, Equal};
+use core::iter::{FusedIterator, DoubleEndedIterator};
+use core::mem;
+#[cfg(not(feature = "std"))]
+use core::net::{IpAddr, Ipv4Addr, Ipv6Addr};
+#[cfg(feature = "std")]
 use std::net::{IpAddr, Ipv4Addr, Ipv6Addr};
 
 /// Provides a `saturating_add()` method for `Ipv4Addr` and `Ipv6Addr`.
@@ -18,6 +21,10 @@ use std::net::{IpAddr, Ipv4Addr, Ipv6Addr};
 /// # Examples
 ///
 /// ```
+/// # #![cfg_attr(not(feature = "std"), feature(ip_in_core))]
+/// # #[cfg(not(feature = "std"))]
+/// # use core::net::{Ipv4Addr, Ipv6Addr};
+/// # #[cfg(feature = "std")]
 /// use std::net::{Ipv4Addr, Ipv6Addr};
 /// use ipnet::IpAdd;
 ///
@@ -58,6 +65,10 @@ pub trait IpAdd<RHS = Self> {
 /// # Examples
 ///
 /// ```
+/// # #![cfg_attr(not(feature = "std"), feature(ip_in_core))]
+/// # #[cfg(not(feature = "std"))]
+/// # use core::net::{Ipv4Addr, Ipv6Addr};
+/// # #[cfg(feature = "std")]
 /// use std::net::{Ipv4Addr, Ipv6Addr};
 /// use ipnet::IpSub;
 ///
@@ -89,6 +100,10 @@ pub trait IpSub<RHS = Self> {
 /// # Examples
 ///
 /// ```
+/// # #![cfg_attr(not(feature = "std"), feature(ip_in_core))]
+/// # #[cfg(not(feature = "std"))]
+/// # use core::net::{Ipv4Addr, Ipv6Addr};
+/// # #[cfg(feature = "std")]
 /// use std::net::{Ipv4Addr, Ipv6Addr};
 /// use ipnet::IpBitAnd;
 ///
@@ -116,6 +131,10 @@ pub trait IpBitAnd<RHS = Self> {
 /// # Examples
 ///
 /// ```
+/// # #![cfg_attr(not(feature = "std"), feature(ip_in_core))]
+/// # #[cfg(not(feature = "std"))]
+/// # use core::net::{Ipv4Addr, Ipv6Addr};
+/// # #[cfg(feature = "std")]
 /// use std::net::{Ipv4Addr, Ipv6Addr};
 /// use ipnet::IpBitOr;
 ///
@@ -290,6 +309,10 @@ pub enum IpAddrRange {
 /// # Examples
 ///
 /// ```
+/// # #![cfg_attr(not(feature = "std"), feature(ip_in_core))]
+/// # #[cfg(not(feature = "std"))]
+/// # use core::net::Ipv4Addr;
+/// # #[cfg(feature = "std")]
 /// use std::net::Ipv4Addr;
 /// use ipnet::Ipv4AddrRange;
 ///
@@ -315,7 +338,11 @@ pub struct Ipv4AddrRange {
 ///
 /// # Examples
 ///
-/// ```
+/// ``` 
+/// # #![cfg_attr(not(feature = "std"), feature(ip_in_core))]
+/// # #[cfg(not(feature = "std"))]
+/// # use core::net::Ipv6Addr;
+/// # #[cfg(feature = "std")]
 /// use std::net::Ipv6Addr;
 /// use ipnet::Ipv6AddrRange;
 ///
@@ -481,12 +508,12 @@ impl Iterator for Ipv4AddrRange {
                 // so need to explicitly check for overflow.
                 // 'usize::MAX as u32' is okay here - if usize is 64 bits,
                 // value truncates to u32::MAX
-                if count <= std::usize::MAX as u32 {
+                if count <= core::usize::MAX as u32 {
                     count as usize + 1
                 // count overflows usize
                 } else {
                     // emulate standard overflow/panic behavior
-                    std::usize::MAX + 2 + count as usize
+                    core::usize::MAX + 2 + count as usize
                 }
             },
             Some(Equal) => 1,
@@ -531,8 +558,8 @@ impl Iterator for Ipv4AddrRange {
 
     fn size_hint(&self) -> (usize, Option<usize>) {
         let count = self.count_u64();
-        if count > std::usize::MAX as u64 {
-            (std::usize::MAX, None)
+        if count > core::usize::MAX as u64 {
+            (core::usize::MAX, None)
         } else {
             let count = count as usize;
             (count, Some(count))
@@ -561,12 +588,12 @@ impl Iterator for Ipv6AddrRange {
     fn count(self) -> usize {
         let count = self.count_u128();
         // count fits in usize
-        if count <= std::usize::MAX as u128 {
+        if count <= core::usize::MAX as u128 {
             count as usize
         // count does not fit in usize
         } else {
             // emulate standard overflow/panic behavior
-            std::usize::MAX + 1 + count as usize
+            core::usize::MAX + 1 + count as usize
         }
     }
 
@@ -616,14 +643,14 @@ impl Iterator for Ipv6AddrRange {
     fn size_hint(&self) -> (usize, Option<usize>) {
         if self.can_count_u128() {
             let count = self.count_u128();
-            if count > std::usize::MAX as u128 {
-                (std::usize::MAX, None)
+            if count > core::usize::MAX as u128 {
+                (core::usize::MAX, None)
             } else {
                 let count = count as usize;
                 (count, Some(count))
             }
         } else {
-            (std::usize::MAX, None)
+            (core::usize::MAX, None)
         }
     }
 }
@@ -722,8 +749,12 @@ impl FusedIterator for Ipv6AddrRange {}
 
 #[cfg(test)]
 mod tests {
+    use alloc::vec::Vec;
+    use core::str::FromStr;
+    #[cfg(not(feature = "std"))]
+    use core::net::{IpAddr, Ipv4Addr, Ipv6Addr};
+    #[cfg(feature = "std")]
     use std::net::{IpAddr, Ipv4Addr, Ipv6Addr};
-    use std::str::FromStr;
     use super::*;
 
     #[test]
@@ -876,7 +907,7 @@ mod tests {
             Ipv6Addr::from_str("::").unwrap(),
             Ipv6Addr::from_str("8000::").unwrap(),
         );
-        assert_eq!(i.size_hint(), (std::usize::MAX, None));
+        assert_eq!(i.size_hint(), (core::usize::MAX, None));
 
         // Min, Max, Last
         let i = Ipv4AddrRange::new(
diff --git a/src/ipnet.rs b/src/ipnet.rs
index e190f06..3875d2c 100644
--- a/src/ipnet.rs
+++ b/src/ipnet.rs
@@ -1,11 +1,18 @@
-use std::cmp::{min, max};
-use std::cmp::Ordering::{Less, Equal};
-use std::convert::From;
+use alloc::vec::Vec;
+use core::cmp::{min, max};
+use core::cmp::Ordering::{Less, Equal};
+use core::convert::From;
+use core::fmt;
+use core::iter::FusedIterator;
+use core::option::Option::{Some, None};
+#[cfg(not(feature = "std"))]
+use core::error::Error;
+#[cfg(feature = "std")]
 use std::error::Error;
-use std::fmt;
-use std::iter::FusedIterator;
+#[cfg(not(feature = "std"))]
+use core::net::{IpAddr, Ipv4Addr, Ipv6Addr};
+#[cfg(feature = "std")]
 use std::net::{IpAddr, Ipv4Addr, Ipv6Addr};
-use std::option::Option::{Some, None};
 
 use crate::ipext::{IpAdd, IpSub, IpStep, IpAddrRange, Ipv4AddrRange, Ipv6AddrRange};
 use crate::mask::{ip_mask_to_prefix, ipv4_mask_to_prefix, ipv6_mask_to_prefix};
@@ -64,7 +71,11 @@ pub enum IpNet {
 /// # Examples
 ///
 /// ```
-/// use std::net::Ipv4Addr;
+/// # #![cfg_attr(not(feature = "std"), feature(ip_in_core))]
+/// # #[cfg(feature = "std")]
+/// # use std::net::Ipv6Addr;
+/// # #[cfg(not(feature = "std"))]
+/// # use core::net::Ipv6Addr;
 /// use ipnet::Ipv4Net;
 ///
 /// let net: Ipv4Net = "10.1.1.0/24".parse().unwrap();
@@ -882,7 +893,7 @@ impl Ipv4Net {
         let mut res: Vec<Ipv4Net> = Vec::new();
         
         for (start, mut end) in intervals {
-            if end != std::u32::MAX {
+            if end != core::u32::MAX {
                 end = end.saturating_sub(1)
             }
             let iter = Ipv4Subnets::new(start.into(), end.into(), 0);
@@ -1227,7 +1238,7 @@ impl Ipv6Net {
         let mut res: Vec<Ipv6Net> = Vec::new();
 
         for (start, mut end) in intervals {
-            if end != std::u128::MAX {
+            if end != core::u128::MAX {
                 end = end.saturating_sub(1)
             }
             let iter = Ipv6Subnets::new(start.into(), end.into(), 0);
@@ -1507,7 +1518,7 @@ impl Iterator for IpSubnets {
 
 fn next_ipv4_subnet(start: Ipv4Addr, end: Ipv4Addr, min_prefix_len: u8) -> Ipv4Net {
     let range = end.saturating_sub(start).saturating_add(1);
-    if range == std::u32::MAX && min_prefix_len == 0 {
+    if range == core::u32::MAX && min_prefix_len == 0 {
         Ipv4Net::new(start, min_prefix_len).unwrap()
     }
     else {
@@ -1521,7 +1532,7 @@ fn next_ipv4_subnet(start: Ipv4Addr, end: Ipv4Addr, min_prefix_len: u8) -> Ipv4N
 
 fn next_ipv6_subnet(start: Ipv6Addr, end: Ipv6Addr, min_prefix_len: u8) -> Ipv6Net {
     let range = end.saturating_sub(start).saturating_add(1);
-    if range == std::u128::MAX && min_prefix_len == 0 {
+    if range == core::u128::MAX && min_prefix_len == 0 {
         Ipv6Net::new(start, min_prefix_len).unwrap()
     }
     else {
diff --git a/src/ipnet_serde.rs b/src/ipnet_serde.rs
index bbf15ac..e42df68 100644
--- a/src/ipnet_serde.rs
+++ b/src/ipnet_serde.rs
@@ -1,5 +1,5 @@
 use crate::{IpNet, Ipv4Net, Ipv6Net};
-use std::fmt;
+use core::fmt;
 use std::net::{Ipv4Addr, Ipv6Addr};
 use serde::{self, Serialize, Deserialize, Serializer, Deserializer};
 use serde::ser::SerializeTuple;
diff --git a/src/lib.rs b/src/lib.rs
index 4f8fb16..8eae5e5 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -78,6 +78,16 @@
 //!
 //! [feature]: https://doc.rust-lang.org/cargo/reference/manifest.html#the-features-section
 
+#![no_std]
+#![cfg_attr(not(feature = "std"), feature(error_in_core))]
+#![cfg_attr(not(feature = "std"), feature(ip_in_core))]
+
+#[cfg(feature = "std")]
+extern crate std;
+
+#[cfg_attr(test, macro_use)]
+extern crate alloc;
+
 #[cfg(feature = "serde")]
 extern crate serde;
 #[cfg(feature = "schemars")]
diff --git a/src/mask.rs b/src/mask.rs
index 1047bf9..761c031 100644
--- a/src/mask.rs
+++ b/src/mask.rs
@@ -1,4 +1,7 @@
 use crate::PrefixLenError;
+#[cfg(not(feature = "std"))]
+use core::net::{IpAddr, Ipv4Addr, Ipv6Addr};
+#[cfg(feature = "std")]
 use std::net::{IpAddr, Ipv4Addr, Ipv6Addr};
 
 /// Converts a `IpAddr` network mask into a prefix.
diff --git a/src/parser.rs b/src/parser.rs
index 7ec9991..d21fe60 100644
--- a/src/parser.rs
+++ b/src/parser.rs
@@ -4,10 +4,16 @@
 //! is private. It is copied and extended here with methods for parsing
 //! IP network addresses.
 
+use alloc::{str::FromStr, boxed::Box};
+use core::fmt;
+#[cfg(not(feature = "std"))]
+use core::error::Error;
+#[cfg(feature = "std")]
 use std::error::Error;
-use std::fmt;
+#[cfg(not(feature = "std"))]
+use core::net::{Ipv4Addr, Ipv6Addr};
+#[cfg(feature = "std")]
 use std::net::{Ipv4Addr, Ipv6Addr};
-use std::str::FromStr;
 
 use crate::ipnet::{IpNet, Ipv4Net, Ipv6Net};