diff --git a/src/imports.rs b/src/imports.rs
index 4f0cb75..ef6a0e9 100644
--- a/src/imports.rs
+++ b/src/imports.rs
@@ -1,12 +1,10 @@
 use std::collections::HashMap;
-use parity_wasm::elements::MemoryType;
 use global::GlobalRef;
 use memory::MemoryRef;
 use func::FuncRef;
 use table::TableRef;
 use module::ModuleRef;
-use types::GlobalDescriptor;
-use types::TableDescriptor;
+use types::{GlobalDescriptor, TableDescriptor, MemoryDescriptor};
 use {Error, Signature};
 
 pub trait ImportResolver {
@@ -28,7 +26,7 @@ pub trait ImportResolver {
 		&self,
 		module_name: &str,
 		field_name: &str,
-		memory_type: &MemoryType,
+		memory_type: &MemoryDescriptor,
 	) -> Result<MemoryRef, Error>;
 
 	fn resolve_table(
@@ -99,7 +97,7 @@ impl<'a> ImportResolver for ImportsBuilder<'a> {
 		&self,
 		module_name: &str,
 		field_name: &str,
-		memory_type: &MemoryType,
+		memory_type: &MemoryDescriptor,
 	) -> Result<MemoryRef, Error> {
 		self.resolver(module_name).ok_or_else(||
 			Error::Instantiation(format!("Module {} not found", module_name))
@@ -142,7 +140,7 @@ pub trait ModuleImportResolver {
 	fn resolve_memory(
 		&self,
 		field_name: &str,
-		_memory_type: &MemoryType,
+		_memory_type: &MemoryDescriptor,
 	) -> Result<MemoryRef, Error> {
 		Err(Error::Instantiation(
 			format!("Export {} not found", field_name),
@@ -194,7 +192,7 @@ impl ModuleImportResolver for ModuleRef {
 	fn resolve_memory(
 		&self,
 		field_name: &str,
-		_memory_type: &MemoryType,
+		_memory_type: &MemoryDescriptor,
 	) -> Result<MemoryRef, Error> {
 		Ok(self.export_by_name(field_name)
 			.ok_or_else(|| {
diff --git a/src/lib.rs b/src/lib.rs
index e31e939..da44a23 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -135,7 +135,7 @@ pub use self::imports::{ModuleImportResolver, ImportResolver, ImportsBuilder};
 pub use self::module::{ModuleInstance, ModuleRef, ExternVal, NotStartedModuleRef};
 pub use self::global::{GlobalInstance, GlobalRef};
 pub use self::func::{FuncInstance, FuncRef};
-pub use self::types::{Signature, ValueType, GlobalDescriptor, TableDescriptor};
+pub use self::types::{Signature, ValueType, GlobalDescriptor, TableDescriptor, MemoryDescriptor};
 
 pub struct LoadedModule {
 	labels: HashMap<usize, HashMap<usize, usize>>,
diff --git a/src/module.rs b/src/module.rs
index 37e05bc..fb0b5c5 100644
--- a/src/module.rs
+++ b/src/module.rs
@@ -12,7 +12,7 @@ use table::TableRef;
 use memory::MemoryRef;
 use host::Externals;
 use common::{DEFAULT_MEMORY_INDEX, DEFAULT_TABLE_INDEX};
-use types::{GlobalDescriptor, TableDescriptor};
+use types::{GlobalDescriptor, TableDescriptor, MemoryDescriptor};
 
 #[derive(Clone, Debug)]
 pub struct ModuleRef(Rc<ModuleInstance>);
@@ -396,7 +396,8 @@ impl ModuleInstance {
 					ExternVal::Table(table)
 				}
 				External::Memory(ref memory_type) => {
-					let memory = imports.resolve_memory(module_name, field_name, memory_type)?;
+					let memory_descriptor = MemoryDescriptor::from_elements(memory_type);
+					let memory = imports.resolve_memory(module_name, field_name, &memory_descriptor)?;
 					ExternVal::Memory(memory)
 				}
 				External::Global(ref global_type) => {
diff --git a/src/tests/host.rs b/src/tests/host.rs
index 318532d..c96a2d9 100644
--- a/src/tests/host.rs
+++ b/src/tests/host.rs
@@ -1,9 +1,7 @@
-
-use parity_wasm::elements::MemoryType;
 use {
 	Error, Signature, Externals, FuncInstance, FuncRef, HostError, ImportsBuilder,
 	MemoryInstance, MemoryRef, TableInstance, TableRef, ModuleImportResolver, ModuleInstance, ModuleRef,
-	RuntimeValue, TryInto, LoadedModule, load_from_buffer, TableDescriptor,
+	RuntimeValue, TryInto, LoadedModule, load_from_buffer, TableDescriptor, MemoryDescriptor,
 };
 use types::ValueType;
 use wabt::wat2wasm;
@@ -195,7 +193,7 @@ impl ModuleImportResolver for TestHost {
 	fn resolve_memory(
 		&self,
 		field_name: &str,
-		_memory_type: &MemoryType,
+		_memory_type: &MemoryDescriptor,
 	) -> Result<MemoryRef, Error> {
 		Err(Error::Instantiation(
 			format!("Export {} not found", field_name),
@@ -443,7 +441,7 @@ fn defer_providing_externals() {
 		fn resolve_memory(
 			&self,
 			field_name: &str,
-			_memory_type: &MemoryType,
+			_memory_type: &MemoryDescriptor,
 		) -> Result<MemoryRef, Error> {
 			if field_name == "mem" {
 				Ok(self.mem.clone())
diff --git a/src/tests/wasm.rs b/src/tests/wasm.rs
index 05144b5..f86594f 100644
--- a/src/tests/wasm.rs
+++ b/src/tests/wasm.rs
@@ -1,8 +1,7 @@
-use parity_wasm::elements::MemoryType;
 use {
 	Error, Signature, FuncRef, GlobalInstance, GlobalRef, ImportsBuilder, MemoryInstance,
     MemoryRef, ModuleImportResolver, ModuleInstance, NopExternals, RuntimeValue,
-    TableInstance, TableRef, LoadedModule, load_from_buffer, GlobalDescriptor, TableDescriptor,
+    TableInstance, TableRef, LoadedModule, load_from_buffer, GlobalDescriptor, TableDescriptor, MemoryDescriptor,
 };
 use std::fs::File;
 
@@ -49,7 +48,7 @@ impl ModuleImportResolver for Env {
 	fn resolve_memory(
 		&self,
 		field_name: &str,
-		_memory_type: &MemoryType,
+		_memory_type: &MemoryDescriptor,
 	) -> Result<MemoryRef, Error> {
 		match field_name {
 			"memory" => Ok(self.memory.clone()),
diff --git a/src/types.rs b/src/types.rs
index 3d65fa0..01c7c25 100644
--- a/src/types.rs
+++ b/src/types.rs
@@ -1,4 +1,5 @@
-use parity_wasm::elements::{FunctionType, ValueType as EValueType, GlobalType, TableType};
+use parity_wasm::elements::{
+	FunctionType, ValueType as EValueType, GlobalType, TableType, MemoryType};
 
 #[derive(Debug, Clone, PartialEq)]
 pub struct Signature {
@@ -101,3 +102,25 @@ impl TableDescriptor {
 		self.maximum
 	}
 }
+
+pub struct MemoryDescriptor {
+	initial: u32,
+	maximum: Option<u32>,
+}
+
+impl MemoryDescriptor {
+	pub(crate) fn from_elements(memory_type: &MemoryType) -> MemoryDescriptor {
+		MemoryDescriptor {
+			initial: memory_type.limits().initial(),
+			maximum: memory_type.limits().maximum(),
+		}
+	}
+
+	pub fn initial(&self) -> u32 {
+		self.initial
+	}
+
+	pub fn maximum(&self) -> Option<u32> {
+		self.maximum
+	}	
+}