diff --git a/miniz_oxide/Cargo.toml b/miniz_oxide/Cargo.toml
index 7993ddbe..2975dda4 100644
--- a/miniz_oxide/Cargo.toml
+++ b/miniz_oxide/Cargo.toml
@@ -12,14 +12,10 @@ documentation = "https://docs.rs/miniz_oxide"
 description = "DEFLATE compression and decompression library rewritten in Rust based on miniz"
 edition = "2018"
 exclude = ["benches/*", "tests/*"]
-build = "build.rs"
 
 [lib]
 name = "miniz_oxide"
 
-[build-dependencies]
-autocfg = "1.0"
-
 [dependencies]
 adler = { version = "1.0", default-features = false }
 simd-adler32 = { version = "0.3", default-features = false, optional = true }
diff --git a/miniz_oxide/build.rs b/miniz_oxide/build.rs
deleted file mode 100755
index e916ace1..00000000
--- a/miniz_oxide/build.rs
+++ /dev/null
@@ -1,6 +0,0 @@
-#![forbid(unsafe_code)]
-use autocfg;
-
-fn main() {
-    autocfg::new().emit_sysroot_crate("alloc");
-}
diff --git a/miniz_oxide/src/deflate/core.rs b/miniz_oxide/src/deflate/core.rs
index c02bcc95..6b6f90a4 100644
--- a/miniz_oxide/src/deflate/core.rs
+++ b/miniz_oxide/src/deflate/core.rs
@@ -2357,8 +2357,7 @@ mod test {
         MZ_DEFAULT_WINDOW_BITS,
     };
     use crate::inflate::decompress_to_vec;
-    use std::prelude::v1::*;
-    use std::vec;
+    use alloc::vec;
 
     #[test]
     fn u16_to_slice() {
diff --git a/miniz_oxide/src/deflate/mod.rs b/miniz_oxide/src/deflate/mod.rs
index cc90ca67..471b94b9 100644
--- a/miniz_oxide/src/deflate/mod.rs
+++ b/miniz_oxide/src/deflate/mod.rs
@@ -160,7 +160,7 @@ fn compress_to_vec_inner(input: &[u8], level: u8, window_bits: i32, strategy: i3
 mod test {
     use super::{compress_to_vec, compress_to_vec_inner, CompressionStrategy};
     use crate::inflate::decompress_to_vec;
-    use std::vec;
+    use alloc::vec;
 
     /// Test deflate example.
     ///
diff --git a/miniz_oxide/src/deflate/stream.rs b/miniz_oxide/src/deflate/stream.rs
index c5ebedb2..3efd8b6e 100644
--- a/miniz_oxide/src/deflate/stream.rs
+++ b/miniz_oxide/src/deflate/stream.rs
@@ -100,8 +100,8 @@ mod test {
     use crate::deflate::CompressorOxide;
     use crate::inflate::decompress_to_vec_zlib;
     use crate::{MZFlush, MZStatus};
-    use std::prelude::v1::*;
-    use std::vec;
+    use alloc::vec;
+    use alloc::boxed::Box;
 
     #[test]
     fn test_state() {
diff --git a/miniz_oxide/src/inflate/stream.rs b/miniz_oxide/src/inflate/stream.rs
index 9fad6561..4a57d5dc 100644
--- a/miniz_oxide/src/inflate/stream.rs
+++ b/miniz_oxide/src/inflate/stream.rs
@@ -351,7 +351,7 @@ fn push_dict_out(state: &mut InflateState, next_out: &mut &mut [u8]) -> usize {
 mod test {
     use super::{inflate, InflateState};
     use crate::{DataFormat, MZFlush, MZStatus};
-    use std::vec;
+    use alloc::vec;
 
     #[test]
     fn test_state() {
diff --git a/miniz_oxide/src/lib.rs b/miniz_oxide/src/lib.rs
index 1c329a47..c63278d2 100644
--- a/miniz_oxide/src/lib.rs
+++ b/miniz_oxide/src/lib.rs
@@ -23,16 +23,9 @@
 
 #![allow(warnings)]
 #![forbid(unsafe_code)]
-#![cfg_attr(any(has_alloc, feature = "rustc-dep-of-std"), no_std)]
+#![no_std]
 
-// autocfg does not work when building in libstd, so manually enable this for that use case now.
-#[cfg(any(has_alloc, feature = "rustc-dep-of-std"))]
 extern crate alloc;
-#[cfg(all(not(has_alloc), not(feature = "rustc-dep-of-std")))]
-use std as alloc;
-
-#[cfg(test)]
-extern crate std;
 
 pub mod deflate;
 pub mod inflate;