diff --git a/Cargo.toml b/Cargo.toml
index 3e84e63..3ab4e31 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -35,6 +35,8 @@ std = [
 ]
 # Enable for no_std support
 core = [
+    # `core` doesn't support vec_memory
+    "vec_memory",
     "wasmi-validation/core",
     "libm"
 ]
diff --git a/src/func.rs b/src/func.rs
index 5cc4a15..1a95f1f 100644
--- a/src/func.rs
+++ b/src/func.rs
@@ -1,6 +1,7 @@
-#[allow(unused_imports)]
-use alloc::prelude::v1::*;
-use alloc::rc::{Rc, Weak};
+use alloc::{
+    rc::{Rc, Weak},
+    vec::Vec,
+};
 use core::fmt;
 use host::Externals;
 use isa;
diff --git a/src/imports.rs b/src/imports.rs
index 10c6a73..17f7a42 100644
--- a/src/imports.rs
+++ b/src/imports.rs
@@ -1,7 +1,4 @@
-#[allow(unused_imports)]
-use alloc::prelude::v1::*;
-
-use alloc::collections::BTreeMap;
+use alloc::{collections::BTreeMap, string::String};
 
 use func::FuncRef;
 use global::GlobalRef;
diff --git a/src/isa.rs b/src/isa.rs
index fcb3905..1981706 100644
--- a/src/isa.rs
+++ b/src/isa.rs
@@ -67,8 +67,7 @@
 //! - Reserved immediates are ignored for `call_indirect`, `current_memory`, `grow_memory`.
 //!
 
-#[allow(unused_imports)]
-use alloc::prelude::v1::*;
+use alloc::vec::Vec;
 
 /// Should we keep a value before "discarding" a stack frame?
 ///
diff --git a/src/lib.rs b/src/lib.rs
index c403623..610723f 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -96,8 +96,6 @@
 
 #![warn(missing_docs)]
 #![cfg_attr(not(feature = "std"), no_std)]
-//// alloc is required in no_std
-#![cfg_attr(not(feature = "std"), feature(alloc, alloc_prelude))]
 
 #[cfg(not(feature = "std"))]
 #[macro_use]
@@ -119,8 +117,11 @@ extern crate parity_wasm;
 
 extern crate wasmi_validation as validation;
 
-#[allow(unused_imports)]
-use alloc::prelude::v1::*;
+use alloc::{
+    boxed::Box,
+    string::{String, ToString},
+    vec::Vec,
+};
 use core::fmt;
 #[cfg(feature = "std")]
 use std::error;
diff --git a/src/memory/mod.rs b/src/memory/mod.rs
index b2d2d8d..f438234 100644
--- a/src/memory/mod.rs
+++ b/src/memory/mod.rs
@@ -1,6 +1,4 @@
-#[allow(unused_imports)]
-use alloc::prelude::v1::*;
-use alloc::rc::Rc;
+use alloc::{rc::Rc, string::ToString, vec::Vec};
 use core::{
     cell::{Cell, RefCell},
     cmp, fmt,
diff --git a/src/memory/vec_bytebuf.rs b/src/memory/vec_bytebuf.rs
index bc5595d..b51c10d 100644
--- a/src/memory/vec_bytebuf.rs
+++ b/src/memory/vec_bytebuf.rs
@@ -1,6 +1,6 @@
 //! An implementation of `ByteBuf` based on a plain `Vec`.
 
-use alloc::prelude::v1::*;
+use alloc::vec::Vec;
 
 pub struct ByteBuf {
     buf: Vec<u8>,
diff --git a/src/module.rs b/src/module.rs
index dbcbc99..493cf30 100644
--- a/src/module.rs
+++ b/src/module.rs
@@ -1,6 +1,9 @@
-#[allow(unused_imports)]
-use alloc::prelude::v1::*;
-use alloc::rc::Rc;
+use alloc::{
+    borrow::ToOwned,
+    rc::Rc,
+    string::{String, ToString},
+    vec::Vec,
+};
 use core::cell::RefCell;
 use core::fmt;
 use Trap;
diff --git a/src/nan_preserving_float.rs b/src/nan_preserving_float.rs
index e63d476..994c91a 100644
--- a/src/nan_preserving_float.rs
+++ b/src/nan_preserving_float.rs
@@ -1,8 +1,5 @@
 #![allow(missing_docs)]
 
-#[cfg(not(feature = "std"))]
-use libm::{F32Ext, F64Ext};
-
 use core::cmp::{Ordering, PartialEq, PartialOrd};
 use core::ops::{Add, Div, Mul, Neg, Rem, Sub};
 
diff --git a/src/prepare/compile.rs b/src/prepare/compile.rs
index 1292772..233ea65 100644
--- a/src/prepare/compile.rs
+++ b/src/prepare/compile.rs
@@ -1,5 +1,4 @@
-#[allow(unused_imports)]
-use alloc::prelude::v1::*;
+use alloc::{string::String, vec::Vec};
 
 use parity_wasm::elements::{BlockType, FuncBody, Instruction};
 
diff --git a/src/prepare/mod.rs b/src/prepare/mod.rs
index 874eeb8..f0d4d34 100644
--- a/src/prepare/mod.rs
+++ b/src/prepare/mod.rs
@@ -1,5 +1,4 @@
-#[allow(unused_imports)]
-use alloc::prelude::v1::*;
+use alloc::vec::Vec;
 
 use crate::{
     isa,
diff --git a/src/runner.rs b/src/runner.rs
index b969116..bcc1853 100644
--- a/src/runner.rs
+++ b/src/runner.rs
@@ -1,5 +1,4 @@
-#[allow(unused_imports)]
-use alloc::prelude::v1::*;
+use alloc::{boxed::Box, vec::Vec};
 use core::fmt;
 use core::ops;
 use core::{u32, usize};
diff --git a/src/table.rs b/src/table.rs
index 63b633f..479912b 100644
--- a/src/table.rs
+++ b/src/table.rs
@@ -1,6 +1,4 @@
-#[allow(unused_imports)]
-use alloc::prelude::v1::*;
-use alloc::rc::Rc;
+use alloc::{rc::Rc, vec::Vec};
 use core::cell::RefCell;
 use core::fmt;
 use core::u32;
diff --git a/validation/src/context.rs b/validation/src/context.rs
index e7de32b..619e5c7 100644
--- a/validation/src/context.rs
+++ b/validation/src/context.rs
@@ -1,6 +1,5 @@
 use crate::Error;
-#[allow(unused_imports)]
-use alloc::prelude::v1::*;
+use alloc::vec::Vec;
 use parity_wasm::elements::{
     BlockType, FunctionType, GlobalType, MemoryType, TableType, ValueType,
 };
diff --git a/validation/src/func.rs b/validation/src/func.rs
index 23e72f4..654bdbd 100644
--- a/validation/src/func.rs
+++ b/validation/src/func.rs
@@ -1,6 +1,3 @@
-#[allow(unused_imports)]
-use alloc::prelude::v1::*;
-
 use crate::{
     context::ModuleContext, stack::StackWithLimit, util::Locals, Error, FuncValidator,
     DEFAULT_MEMORY_INDEX, DEFAULT_TABLE_INDEX,
diff --git a/validation/src/lib.rs b/validation/src/lib.rs
index 4815b0a..72e9ef7 100644
--- a/validation/src/lib.rs
+++ b/validation/src/lib.rs
@@ -2,8 +2,6 @@
 // #![warn(missing_docs)]
 
 #![cfg_attr(not(feature = "std"), no_std)]
-//// alloc is required in no_std
-#![cfg_attr(not(feature = "std"), feature(alloc, alloc_prelude))]
 
 #[cfg(not(feature = "std"))]
 #[macro_use]
@@ -21,8 +19,7 @@ pub const DEFAULT_TABLE_INDEX: u32 = 0;
 /// Maximal number of pages that a wasm instance supports.
 pub const LINEAR_MEMORY_MAX_PAGES: u32 = 65536;
 
-#[allow(unused_imports)]
-use alloc::prelude::v1::*;
+use alloc::{string::String, vec::Vec};
 use core::fmt;
 #[cfg(feature = "std")]
 use std::error;
diff --git a/validation/src/stack.rs b/validation/src/stack.rs
index 6f1166a..60e62da 100644
--- a/validation/src/stack.rs
+++ b/validation/src/stack.rs
@@ -1,5 +1,4 @@
-#[allow(unused_imports)]
-use alloc::prelude::v1::*;
+use alloc::{string::String, vec::Vec};
 
 use core::fmt;
 #[cfg(feature = "std")]
diff --git a/validation/src/util.rs b/validation/src/util.rs
index 5f320e9..2c44a4e 100644
--- a/validation/src/util.rs
+++ b/validation/src/util.rs
@@ -1,6 +1,5 @@
 use crate::Error;
-#[allow(unused_imports)]
-use alloc::prelude::v1::*;
+use alloc::string::String;
 use parity_wasm::elements::{Local, ValueType};
 
 #[cfg(test)]