diff --git a/src/ext.rs b/src/ext.rs
index bba1777..479d770 100644
--- a/src/ext.rs
+++ b/src/ext.rs
@@ -1,4 +1,5 @@
 use parity_wasm::{elements, builder};
+use optimizer::import_section;
 
 type Insertion = (usize, u32, u32, String);
 
@@ -37,6 +38,14 @@ pub fn externalize_mem(mut module: elements::Module) -> elements::Module {
 		.pop()
 		.expect("Own memory entry to exist in memory section");
 
+	import_section(&mut module).expect("Import section to exist").entries_mut().push(
+		elements::ImportEntry::new(
+			"env".to_owned(),
+			"memory".to_owned(),
+			elements::External::Memory(entry),
+		)
+	);
+
 	module
 }
 
diff --git a/src/lib.rs b/src/lib.rs
index 1e994a3..6fe4b75 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -21,7 +21,7 @@ mod runtime_type;
 pub use optimizer::{optimize, Error as OptimizerError};
 pub use gas::inject_gas_counter;
 pub use logger::init_log;
-pub use ext::externalize;
+pub use ext::{externalize, externalize_mem};
 pub use pack::pack_instance;
 pub use nondeterminism_check::is_deterministic;
 pub use runtime_type::inject_runtime_type;