diff --git a/cli/Cargo.toml b/cli/Cargo.toml
index 81b9201..d70de10 100644
--- a/cli/Cargo.toml
+++ b/cli/Cargo.toml
@@ -34,7 +34,7 @@ name = "wasm-pack"
 path = "pack/main.rs"
 
 [dependencies]
-parity-wasm = "0.30"
+parity-wasm = "0.31"
 pwasm-utils = { path = "..", version = "0.2" }
 glob = "0.2"
 clap = "2.24"
diff --git a/src/gas.rs b/src/gas.rs
index c189fe1..14f8365 100644
--- a/src/gas.rs
+++ b/src/gas.rs
@@ -271,7 +271,7 @@ mod tests {
 
 	#[test]
 	fn simple_grow() {
-		use parity_wasm::elements::Opcode::*;
+		use parity_wasm::elements::Instruction::*;
 
 		let module = builder::module()
 			.global()
@@ -280,7 +280,7 @@ mod tests {
 			.function()
 				.signature().param().i32().build()
 				.body()
-					.with_opcodes(elements::Opcodes::new(
+					.with_instructions(elements::Instructions::new(
 						vec![
 							GetGlobal(0),
 							GrowMemory(0),
@@ -326,7 +326,7 @@ mod tests {
 
 	#[test]
 	fn grow_no_gas_no_track() {
-		use parity_wasm::elements::Opcode::*;
+		use parity_wasm::elements::Instruction::*;
 
 		let module = builder::module()
 			.global()
@@ -335,7 +335,7 @@ mod tests {
 			.function()
 				.signature().param().i32().build()
 				.body()
-					.with_opcodes(elements::Opcodes::new(
+					.with_instructions(elements::Instructions::new(
 						vec![
 							GetGlobal(0),
 							GrowMemory(0),
@@ -369,7 +369,7 @@ mod tests {
 
 	#[test]
 	fn simple() {
-		use parity_wasm::elements::Opcode::*;
+		use parity_wasm::elements::Instruction::*;
 
 		let module = builder::module()
 			.global()
@@ -378,7 +378,7 @@ mod tests {
 			.function()
 				.signature().param().i32().build()
 				.body()
-					.with_opcodes(elements::Opcodes::new(
+					.with_instructions(elements::Instructions::new(
 						vec![
 							GetGlobal(0),
 							End
@@ -405,7 +405,7 @@ mod tests {
 
 	#[test]
 	fn nested() {
-		use parity_wasm::elements::Opcode::*;
+		use parity_wasm::elements::Instruction::*;
 
 		let module = builder::module()
 			.global()
@@ -414,7 +414,7 @@ mod tests {
 			.function()
 				.signature().param().i32().build()
 				.body()
-					.with_opcodes(elements::Opcodes::new(
+					.with_instructions(elements::Instructions::new(
 						vec![
 							GetGlobal(0),
 							Block(elements::BlockType::NoResult),
@@ -455,7 +455,7 @@ mod tests {
 
 	#[test]
 	fn ifelse() {
-		use parity_wasm::elements::Opcode::*;
+		use parity_wasm::elements::Instruction::*;
 
 		let module = builder::module()
 			.global()
@@ -464,7 +464,7 @@ mod tests {
 			.function()
 				.signature().param().i32().build()
 				.body()
-					.with_opcodes(elements::Opcodes::new(
+					.with_instructions(elements::Instructions::new(
 						vec![
 							GetGlobal(0),
 							If(elements::BlockType::NoResult),
@@ -513,7 +513,7 @@ mod tests {
 
 	#[test]
 	fn call_index() {
-		use parity_wasm::elements::Opcode::*;
+		use parity_wasm::elements::Instruction::*;
 
 		let module = builder::module()
 			.global()
@@ -526,7 +526,7 @@ mod tests {
 			.function()
 				.signature().param().i32().build()
 				.body()
-					.with_opcodes(elements::Opcodes::new(
+					.with_instructions(elements::Instructions::new(
 						vec![
 							Call(0),
 							If(elements::BlockType::NoResult),
@@ -576,7 +576,7 @@ mod tests {
 
 	#[test]
 	fn forbidden() {
-		use parity_wasm::elements::Opcode::*;
+		use parity_wasm::elements::Instruction::*;
 
 		let module = builder::module()
 			.global()
@@ -585,7 +585,7 @@ mod tests {
 			.function()
 				.signature().param().i32().build()
 				.body()
-					.with_opcodes(elements::Opcodes::new(
+					.with_instructions(elements::Instructions::new(
 						vec![
 							F32Const(555555),
 							End
diff --git a/src/optimizer.rs b/src/optimizer.rs
index 62a37e5..3a2f9d6 100644
--- a/src/optimizer.rs
+++ b/src/optimizer.rs
@@ -435,7 +435,7 @@ mod tests {
 			.function()
 				.signature().param().i32().build()
 				.body()
-					.with_opcodes(elements::Instructions::new(
+					.with_instructions(elements::Instructions::new(
 						vec![
 							elements::Instruction::GetGlobal(0),
 							elements::Instruction::End
@@ -477,7 +477,7 @@ mod tests {
 			.function()
 				.signature().param().i32().build()
 				.body()
-					.with_opcodes(elements::Instructions::new(
+					.with_instructions(elements::Instructions::new(
 						vec![
 							elements::Instruction::GetGlobal(1),
 							elements::Instruction::End
@@ -510,7 +510,7 @@ mod tests {
 			.function()
 				.signature().param().i32().build()
 				.body()
-					.with_opcodes(elements::Instructions::new(
+					.with_instructions(elements::Instructions::new(
 						vec![
 							elements::Instruction::Call(1),
 							elements::Instruction::End
@@ -563,7 +563,7 @@ mod tests {
 			.function()
 				.signature().param().i32().build()
 				.body()
-					.with_opcodes(elements::Instructions::new(
+					.with_instructions(elements::Instructions::new(
 						vec![
 							elements::Instruction::CallIndirect(1, 0),
 							elements::Instruction::End
diff --git a/src/pack.rs b/src/pack.rs
index ee38d34..fc52890 100644
--- a/src/pack.rs
+++ b/src/pack.rs
@@ -249,7 +249,7 @@ mod test {
             .function()
                 .signature().build()
                 .body()
-                    .with_opcodes(elements::Instructions::new(
+                    .with_instructions(elements::Instructions::new(
                         vec![
                             elements::Instruction::End
                         ]
@@ -259,7 +259,7 @@ mod test {
             .function()
                 .signature().build()
                 .body()
-                    .with_opcodes(elements::Instructions::new(
+                    .with_instructions(elements::Instructions::new(
                         vec![
                             elements::Instruction::End
                         ]
@@ -298,7 +298,7 @@ mod test {
             .function()
                 .signature().build()
                 .body()
-                    .with_opcodes(elements::Instructions::new(
+                    .with_instructions(elements::Instructions::new(
                         vec![
                             elements::Instruction::End
                         ]
@@ -308,7 +308,7 @@ mod test {
             .function()
                 .signature().build()
                 .body()
-                    .with_opcodes(elements::Instructions::new(
+                    .with_instructions(elements::Instructions::new(
                         vec![
                             elements::Instruction::End
                         ]