diff --git a/src/build.rs b/src/build.rs
index 5370563..8f742fc 100644
--- a/src/build.rs
+++ b/src/build.rs
@@ -8,6 +8,7 @@ use super::{
 	PackingError,
 	OptimizerError,
 	TargetRuntime,
+	std::fmt,
 };
 use parity_wasm::elements;
 
@@ -36,8 +37,8 @@ pub enum SourceTarget {
 	Unknown,
 }
 
-impl std::fmt::Display for Error {
-	fn fmt(&self, f: &mut std::fmt::Formatter) -> Result<(), std::fmt::Error> {
+impl fmt::Display for Error {
+	fn fmt(&self, f: &mut fmt::Formatter) -> Result<(), fmt::Error> {
 		use self::Error::*;
 		match self {
 			Encoding(err) => write!(f, "Encoding error ({})", err),
diff --git a/src/ext.rs b/src/ext.rs
index 11c5f18..3b129e7 100644
--- a/src/ext.rs
+++ b/src/ext.rs
@@ -1,6 +1,6 @@
-use std::string::String;
-use std::vec::Vec;
-use std::borrow::ToOwned;
+use crate::std::string::String;
+use crate::std::vec::Vec;
+use crate::std::borrow::ToOwned;
 
 use parity_wasm::{elements, builder};
 use byteorder::{LittleEndian, ByteOrder};
diff --git a/src/gas/mod.rs b/src/gas/mod.rs
index 860b1c3..90d63ca 100644
--- a/src/gas/mod.rs
+++ b/src/gas/mod.rs
@@ -7,9 +7,9 @@
 #[cfg(test)]
 mod validation;
 
-use std::cmp::min;
-use std::mem;
-use std::vec::Vec;
+use crate::std::cmp::min;
+use crate::std::mem;
+use crate::std::vec::Vec;
 
 use parity_wasm::{elements, builder};
 use crate::rules::Rules;
diff --git a/src/gas/validation.rs b/src/gas/validation.rs
index 604906c..5f68dcc 100644
--- a/src/gas/validation.rs
+++ b/src/gas/validation.rs
@@ -11,9 +11,13 @@
 use super::MeteredBlock;
 use crate::rules::Set as RuleSet;
 use crate::rules::Rules;
+use crate::std::vec::Vec;
 use parity_wasm::elements::{FuncBody, Instruction};
 
-use std::collections::HashMap;
+#[cfg(features = "std")]
+use crate::std::collections::HashMap as Map;
+#[cfg(not(features = "std"))]
+use crate::std::collections::BTreeMap as Map;
 
 /// An ID for a node in a ControlFlowGraph.
 type NodeId = usize;
@@ -288,7 +292,7 @@ fn validate_graph_gas_costs(graph: &ControlFlowGraph) -> bool {
 		node_id: NodeId,
 		mut total_actual: u32,
 		mut total_charged: u32,
-		loop_costs: &mut HashMap<NodeId, (u32, u32)>,
+		loop_costs: &mut Map<NodeId, (u32, u32)>,
 	) -> bool {
 		let node = graph.get_node(node_id);
 
@@ -325,7 +329,7 @@ fn validate_graph_gas_costs(graph: &ControlFlowGraph) -> bool {
 	}
 
 	// Recursively explore all paths through the execution graph starting from the entry node.
-	visit(graph, 0, 0, 0, &mut HashMap::new())
+	visit(graph, 0, 0, 0, &mut Map::new())
 }
 
 /// Validate that the metered blocks are correct with respect to the function body by exhaustively
diff --git a/src/graph.rs b/src/graph.rs
index 956cc7f..41c4665 100644
--- a/src/graph.rs
+++ b/src/graph.rs
@@ -4,7 +4,7 @@
 
 use parity_wasm::elements;
 use super::ref_list::{RefList, EntryRef};
-use std::{
+use crate::std::{
 	vec::Vec,
 	borrow::ToOwned,
 	string::String,
diff --git a/src/lib.rs b/src/lib.rs
index 081d99f..8b42ccd 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -83,7 +83,7 @@ impl TargetRuntime {
 
 #[cfg(not(feature = "std"))]
 mod std {
-	pub use alloc::{borrow, boxed, string, vec};
+	pub use ::alloc::{borrow, boxed, string, vec};
 	pub use core::*;
 
 	pub mod rc {
@@ -94,3 +94,9 @@ mod std {
 		pub use alloc::collections::{BTreeMap, BTreeSet};
 	}
 }
+
+
+#[cfg(feature = "std")]
+mod std {
+	pub use std::*;
+}
diff --git a/src/logger.rs b/src/logger.rs
index 222ad50..8993eba 100644
--- a/src/logger.rs
+++ b/src/logger.rs
@@ -1,4 +1,4 @@
-use std::env;
+use crate::std::env;
 use log::LevelFilter;
 use env_logger::Builder;
 use lazy_static::lazy_static;
diff --git a/src/optimizer.rs b/src/optimizer.rs
index a123cd6..86fc8b0 100644
--- a/src/optimizer.rs
+++ b/src/optimizer.rs
@@ -1,9 +1,9 @@
 #[cfg(features = "std")]
-use std::collections::{HashSet as Set};
+use crate::std::collections::{HashSet as Set};
 #[cfg(not(features = "std"))]
-use std::collections::{BTreeSet as Set};
-use std::vec::Vec;
-use std::mem;
+use crate::std::collections::{BTreeSet as Set};
+use crate::std::vec::Vec;
+use crate::std::mem;
 
 use parity_wasm::elements;
 
diff --git a/src/pack.rs b/src/pack.rs
index 0816b5f..becda22 100644
--- a/src/pack.rs
+++ b/src/pack.rs
@@ -1,6 +1,6 @@
-use std::fmt;
-use std::vec::Vec;
-use std::borrow::ToOwned;
+use crate::std::fmt;
+use crate::std::vec::Vec;
+use crate::std::borrow::ToOwned;
 
 use parity_wasm::elements::{
 	self, Section, DataSection, Instruction, DataSegment, InitExpr, Internal, External,
diff --git a/src/ref_list.rs b/src/ref_list.rs
index 376486d..1925d8a 100644
--- a/src/ref_list.rs
+++ b/src/ref_list.rs
@@ -1,9 +1,9 @@
 #![warn(missing_docs)]
 
-use std::rc::Rc;
-use std::cell::RefCell;
-use std::vec::Vec;
-use std::slice;
+use crate::std::rc::Rc;
+use crate::std::cell::RefCell;
+use crate::std::vec::Vec;
+use crate::std::slice;
 
 #[derive(Debug)]
 enum EntryOrigin {
@@ -50,7 +50,7 @@ impl<T> Entry<T> {
 	}
 }
 
-impl<T> ::std::ops::Deref for Entry<T> {
+impl<T> crate::std::ops::Deref for Entry<T> {
 	type Target = T;
 
 	fn deref(&self) -> &T {
@@ -58,7 +58,7 @@ impl<T> ::std::ops::Deref for Entry<T> {
 	}
 }
 
-impl<T> ::std::ops::DerefMut for Entry<T> {
+impl<T> crate::std::ops::DerefMut for Entry<T> {
 	fn deref_mut(&mut self) -> &mut T {
 		&mut self.val
 	}
@@ -82,14 +82,14 @@ impl<T> From<Entry<T>> for EntryRef<T> {
 
 impl<T> EntryRef<T> {
 	/// Read the reference data.
-	pub fn read(&self) -> ::std::cell::Ref<Entry<T>> {
+	pub fn read(&self) -> crate::std::cell::Ref<Entry<T>> {
 		self.0.borrow()
 	}
 
 	/// Try to modify internal content of the referenced object.
 	///
 	/// May panic if it is already borrowed.
-	pub fn write(&self) -> ::std::cell::RefMut<Entry<T>> {
+	pub fn write(&self) -> crate::std::cell::RefMut<Entry<T>> {
 		self.0.borrow_mut()
 	}
 
diff --git a/src/rules.rs b/src/rules.rs
index 0cefabf..2256a6c 100644
--- a/src/rules.rs
+++ b/src/rules.rs
@@ -1,9 +1,10 @@
 #[cfg(features = "std")]
-use std::collections::{HashMap as Map};
+use crate::std::collections::HashMap as Map;
 #[cfg(not(features = "std"))]
-use std::collections::{BTreeMap as Map};
+use crate::std::collections::BTreeMap as Map;
 
-use std::num::NonZeroU32;
+use crate::std::num::NonZeroU32;
+use crate::std::str::FromStr;
 
 use parity_wasm::elements;
 
@@ -68,7 +69,7 @@ pub enum InstructionType {
 	GrowMemory,
 }
 
-impl ::std::str::FromStr for InstructionType {
+impl FromStr for InstructionType {
 	type Err = UnknownInstruction;
 
 	fn from_str(s: &str) -> Result<Self, Self::Err> {
diff --git a/src/stack_height/max_height.rs b/src/stack_height/max_height.rs
index 23c7ea1..4849092 100644
--- a/src/stack_height/max_height.rs
+++ b/src/stack_height/max_height.rs
@@ -1,4 +1,4 @@
-use std::vec::Vec;
+use crate::std::vec::Vec;
 
 use parity_wasm::elements::{self, BlockType, Type};
 use super::{resolve_func_type, Error};
diff --git a/src/stack_height/mod.rs b/src/stack_height/mod.rs
index 737d84a..d619f9e 100644
--- a/src/stack_height/mod.rs
+++ b/src/stack_height/mod.rs
@@ -49,8 +49,8 @@
 //!   between the frames.
 //! - upon entry into the function entire stack frame is allocated.
 
-use std::string::String;
-use std::vec::Vec;
+use crate::std::string::String;
+use crate::std::vec::Vec;
 
 use parity_wasm::elements::{self, Type};
 use parity_wasm::builder;
diff --git a/src/stack_height/thunk.rs b/src/stack_height/thunk.rs
index aaa02ee..11a377d 100644
--- a/src/stack_height/thunk.rs
+++ b/src/stack_height/thunk.rs
@@ -1,8 +1,8 @@
 #[cfg(features = "std")]
-use std::collections::{HashMap as Map};
+use crate::std::collections::{HashMap as Map};
 #[cfg(not(features = "std"))]
-use std::collections::{BTreeMap as Map};
-use std::vec::Vec;
+use crate::std::collections::{BTreeMap as Map};
+use crate::std::vec::Vec;
 
 use parity_wasm::elements::{self, FunctionType, Internal};
 use parity_wasm::builder;
diff --git a/src/symbols.rs b/src/symbols.rs
index 60b6ef1..8586e65 100644
--- a/src/symbols.rs
+++ b/src/symbols.rs
@@ -1,8 +1,8 @@
 #[cfg(features = "std")]
-use std::collections::{HashSet as Set};
+use crate::std::collections::{HashSet as Set};
 #[cfg(not(features = "std"))]
-use std::collections::{BTreeSet as Set};
-use std::vec::Vec;
+use crate::std::collections::{BTreeSet as Set};
+use crate::std::vec::Vec;
 
 use parity_wasm::elements;