diff --git a/src/common.rs b/src/common.rs
index e97a214..2d8ad7b 100644
--- a/src/common.rs
+++ b/src/common.rs
@@ -18,7 +18,7 @@
 // is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 // KIND, either express or implied.
 
-use std::ptr;
+use core::ptr;
 
 // Returns e == 0 ? 1 : ceil(log_2(5^e)).
 pub fn pow5bits(e: i32) -> u32 {
diff --git a/src/d2s.rs b/src/d2s.rs
index 256d49d..2c2acaf 100644
--- a/src/d2s.rs
+++ b/src/d2s.rs
@@ -18,7 +18,7 @@
 // is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 // KIND, either express or implied.
 
-use std::{mem, ptr};
+use core::{mem, ptr};
 
 use common::*;
 use d2s_full_table::*;
diff --git a/src/f2s.rs b/src/f2s.rs
index c250a94..30bc912 100644
--- a/src/f2s.rs
+++ b/src/f2s.rs
@@ -18,7 +18,7 @@
 // is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 // KIND, either express or implied.
 
-use std::ptr;
+use core::ptr;
 
 use common::*;
 use digit_table::*;
diff --git a/src/lib.rs b/src/lib.rs
index 5956a18..659e862 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -1,3 +1,4 @@
+#![no_std]
 #![cfg_attr(
     feature = "cargo-clippy",
     allow(