diff --git a/lib/interface-types/src/ast.rs b/lib/interface-types/src/ast.rs
index 28c8682b113..63cb7789f54 100644
--- a/lib/interface-types/src/ast.rs
+++ b/lib/interface-types/src/ast.rs
@@ -37,6 +37,12 @@ pub enum Instruction<'input> {
     GetField(InterfaceType, u64),
     Const(InterfaceType, u64),
     FoldSeq(u64),
+    Add(InterfaceType),
+    MemToSeq(InterfaceType, &'input str),
+    Load(InterfaceType, &'input str),
+    SeqNew(InterfaceType),
+    ListPush,
+    RepeatWhile(u64, u64),
 }
 
 #[derive(PartialEq, Debug)]
diff --git a/lib/interface-types/src/decoders/binary.rs b/lib/interface-types/src/decoders/binary.rs
index f3cedc53b04..b86cdc303cf 100644
--- a/lib/interface-types/src/decoders/binary.rs
+++ b/lib/interface-types/src/decoders/binary.rs
@@ -193,6 +193,36 @@ fn instructions<'input, E: ParseError<&'input [u8]>>(
             (input, Instruction::FoldSeq(argument_0))
         }
 
+        0x0f => {
+            consume!((input, argument_0) = ty(input)?);
+            (input, Instruction::Add(argument_0))
+        }
+
+        0x10 => {
+            consume!((input, argument_0) = ty(input)?);
+            consume!((input, argument_1) = string(input)?);
+            (input, Instruction::MemToSeq(argument_0, argument_1))
+        }
+
+        0x11 => {
+            consume!((input, argument_0) = ty(input)?);
+            consume!((input, argument_1) = string(input)?);
+            (input, Instruction::Load(argument_0, argument_1))
+        }
+
+        0x12 => {
+            consume!((input, argument_0) = ty(input)?);
+            (input, Instruction::SeqNew(argument_0))
+        }
+
+        0x13 => (input, Instruction::ListPush),
+
+        0x14 => {
+            consume!((input, argument_0) = leb(input)?);
+            consume!((input, argument_1) = leb(input)?);
+            (input, Instruction::RepeatWhile(argument_0, argument_1))
+        }
+
         _ => return Err(Err::Error(make_error(input, ErrorKind::ParseTo))),
     })
 }
@@ -467,7 +497,7 @@ mod tests {
     #[test]
     fn test_instructions() {
         let input = &[
-            0x0e, // list of 14 items
+            0x14, // list of 20 items
             0x00, 0x01, // ArgumentGet(1)
             0x01, 0x01, // Call(1)
             0x02, 0x03, 0x61, 0x62, 0x63, // CallExport("abc")
@@ -482,6 +512,12 @@ mod tests {
             0x0c, 0xff, 0xff, 0x01, 0x02, // GetField(Int, 2)
             0x0d, 0x7f, 0x01, // Const(I32, 1)
             0x0e, 0x01, // FoldSeq(1)
+            0x0f, 0x7f, // Add(I32)
+            0x10, 0x7f, 0x03, 0x61, 0x62, 0x63, // MemToSeq(I32, "abc")
+            0x11, 0x7f, 0x03, 0x61, 0x62, 0x63, // Load(I32, "abc")
+            0x12, 0x7f, // SeqNew(I32)
+            0x13, // ListPush
+            0x14, 0x01, 0x02, // RepeatWhile(1, 2)
             0x0a,
         ];
         let output = Ok((
@@ -501,6 +537,12 @@ mod tests {
                 Instruction::GetField(InterfaceType::Int, 2),
                 Instruction::Const(InterfaceType::I32, 1),
                 Instruction::FoldSeq(1),
+                Instruction::Add(InterfaceType::I32),
+                Instruction::MemToSeq(InterfaceType::I32, "abc"),
+                Instruction::Load(InterfaceType::I32, "abc"),
+                Instruction::SeqNew(InterfaceType::I32),
+                Instruction::ListPush,
+                Instruction::RepeatWhile(1, 2),
             ],
         ));
 
diff --git a/lib/interface-types/src/encoders/wat.rs b/lib/interface-types/src/encoders/wat.rs
index eafca5713fe..41f73b473dc 100644
--- a/lib/interface-types/src/encoders/wat.rs
+++ b/lib/interface-types/src/encoders/wat.rs
@@ -44,6 +44,22 @@ impl<'input> From<&Instruction<'input>> for String {
                 format!("const {} {}", String::from(interface_type), value)
             }
             Instruction::FoldSeq(import_index) => format!("fold-seq {}", import_index),
+            Instruction::Add(interface_type) => format!("add {}", String::from(interface_type)),
+            Instruction::MemToSeq(interface_type, memory) => format!(
+                r#"mem-to-seq {} "{}""#,
+                String::from(interface_type),
+                memory
+            ),
+            Instruction::Load(interface_type, memory) => {
+                format!(r#"load {} "{}""#, String::from(interface_type), memory)
+            }
+            Instruction::SeqNew(interface_type) => {
+                format!("seq.new {}", String::from(interface_type))
+            }
+            Instruction::ListPush => "list.push".into(),
+            Instruction::RepeatWhile(condition_index, step_index) => {
+                format!("repeat-while {} {}", condition_index, step_index)
+            }
         }
     }
 }
@@ -212,6 +228,12 @@ mod tests {
             (&Instruction::GetField(InterfaceType::Int, 7)).into(),
             (&Instruction::Const(InterfaceType::I32, 7)).into(),
             (&Instruction::FoldSeq(7)).into(),
+            (&Instruction::Add(InterfaceType::Int)).into(),
+            (&Instruction::MemToSeq(InterfaceType::Int, "foo")).into(),
+            (&Instruction::Load(InterfaceType::Int, "foo")).into(),
+            (&Instruction::SeqNew(InterfaceType::Int)).into(),
+            (&Instruction::ListPush).into(),
+            (&Instruction::RepeatWhile(1, 2)).into(),
         ];
         let outputs = vec![
             "arg.get 7",
@@ -228,6 +250,12 @@ mod tests {
             "get-field Int 7",
             "const i32 7",
             "fold-seq 7",
+            "add Int",
+            r#"mem-to-seq Int "foo""#,
+            r#"load Int "foo""#,
+            "seq.new Int",
+            "list.push",
+            "repeat-while 1 2",
         ];
 
         assert_eq!(inputs, outputs);