diff --git a/crates/abi/src/elements.rs b/crates/abi/src/elements.rs
index ef8b1e8f10..63fd9e1567 100644
--- a/crates/abi/src/elements.rs
+++ b/crates/abi/src/elements.rs
@@ -106,7 +106,7 @@ impl JsonAbi for Base {
             Base::Numeric(Integer::I8) => "int8".to_string(),
             Base::Address => "address".to_string(),
             Base::Bool => "bool".to_string(),
-            Base::Unit => panic!("unit type is not abi encodable"),
+            Base::Unit => "".to_string(),
         }
     }
 }
diff --git a/crates/yulgen/src/db/queries/functions.rs b/crates/yulgen/src/db/queries/functions.rs
index 464160b584..c7c36019d5 100644
--- a/crates/yulgen/src/db/queries/functions.rs
+++ b/crates/yulgen/src/db/queries/functions.rs
@@ -39,6 +39,13 @@ pub fn function_def(db: &dyn YulgenDb, function: FunctionId) -> yul::Statement {
 
     let function_name = identifier! { (db.function_yul_name(function)) };
     // all user-defined functions are given a return value during lowering
+
+    // ^ this is no longer true. functions that return the unit type do not
+    // get a return statement. Need a way to identify what functions don't have a
+    // return statement from here, so we can remove the '-> return_val' in those cases.
+
+    // let has_return_value = function_statements.iter().any(|x| x);
+
     function_definition! {
         function [function_name]([param_names...]) -> return_val {
             [function_statements...]
diff --git a/crates/yulgen/src/mappers/expressions.rs b/crates/yulgen/src/mappers/expressions.rs
index fdbd51c180..b86f230d68 100644
--- a/crates/yulgen/src/mappers/expressions.rs
+++ b/crates/yulgen/src/mappers/expressions.rs
@@ -39,7 +39,13 @@ pub fn expr(context: &mut FnContext, exp: &Node<fe::Expr>) -> yul::Expression {
         fe::Expr::List { .. } => panic!("list expressions should be lowered"),
         fe::Expr::Tuple { .. } => panic!("tuple expressions should be lowered"),
         fe::Expr::Str(_) => expr_str(exp),
-        fe::Expr::Unit => expression! { 0x0 },
+        // fe::Expr::Unit => expression! { 0x0 },
+        fe::Expr::Unit => yultsur::yul::Expression::Literal({
+            yul::Literal {
+                literal: "".to_string(),
+                yultype: None
+            }
+        })
     };
 
     let attributes = context.expression_attributes(exp);
diff --git a/crates/yulgen/src/mappers/functions.rs b/crates/yulgen/src/mappers/functions.rs
index fe92f75786..3d840c986c 100644
--- a/crates/yulgen/src/mappers/functions.rs
+++ b/crates/yulgen/src/mappers/functions.rs
@@ -224,9 +224,16 @@ fn func_return(context: &mut FnContext, stmt: &Node<fe::FuncStmt>) -> yul::State
             .expect("valueless return made it to Yul codegen");
         let value = expressions::expr(context, value);
 
-        block_statement! {
-            (return_val := [value])
-            (leave)
+        if let yul::Expression::Literal(yultype) = value {
+            block_statement! {
+                (leave)
+            }
+        }
+        else {
+            block_statement! {
+                (return_val := [value])
+                (leave)
+            }
         }
     } else {
         unreachable!()
diff --git a/crates/yulgen/src/types.rs b/crates/yulgen/src/types.rs
index ed7a53c307..e6ce3aeca9 100644
--- a/crates/yulgen/src/types.rs
+++ b/crates/yulgen/src/types.rs
@@ -171,11 +171,11 @@ impl AbiType {
 }
 
 pub trait AsAbiType {
-    fn as_abi_type(&self, db: &dyn AnalyzerDb) -> AbiType;
+    fn as_abi_type(&self, db: &dyn AnalyzerDb) -> Option<AbiType>;
 }
 
 impl AsAbiType for FixedSize {
-    fn as_abi_type(&self, db: &dyn AnalyzerDb) -> AbiType {
+    fn as_abi_type(&self, db: &dyn AnalyzerDb) -> Option<AbiType> {
         match self {
             FixedSize::Base(base) => base.as_abi_type(db),
             FixedSize::Array(array) => array.as_abi_type(db),
@@ -188,38 +188,38 @@ impl AsAbiType for FixedSize {
 }
 
 impl AsAbiType for Base {
-    fn as_abi_type(&self, _db: &dyn AnalyzerDb) -> AbiType {
+    fn as_abi_type(&self, _db: &dyn AnalyzerDb) -> Option<AbiType> {
         match self {
             Base::Numeric(integer) => {
                 let size = integer.size();
                 if integer.is_signed() {
-                    AbiType::Int { size }
+                    Some(AbiType::Int { size })
                 } else {
-                    AbiType::Uint { size }
+                    Some(AbiType::Uint { size })
                 }
             }
-            Base::Address => AbiType::Address,
-            Base::Bool => AbiType::Bool,
-            Base::Unit => panic!("unit type is not abi encodable"),
+            Base::Address => Some(AbiType::Address),
+            Base::Bool => Some(AbiType::Bool),
+            Base::Unit => None,
         }
     }
 }
 
 impl AsAbiType for Array {
-    fn as_abi_type(&self, db: &dyn AnalyzerDb) -> AbiType {
+    fn as_abi_type(&self, db: &dyn AnalyzerDb) -> Option<AbiType> {
         if matches!(self.inner, Base::Numeric(Integer::U8)) {
-            AbiType::Bytes { size: self.size }
+            Some(AbiType::Bytes { size: self.size })
         } else {
-            AbiType::StaticArray {
-                inner: Box::new(self.inner.as_abi_type(db)),
+            Some(AbiType::StaticArray {
+                inner: Box::new(self.inner.as_abi_type(db).unwrap()),
                 size: self.size,
-            }
+            })
         }
     }
 }
 
 impl AsAbiType for Struct {
-    fn as_abi_type(&self, db: &dyn AnalyzerDb) -> AbiType {
+    fn as_abi_type(&self, db: &dyn AnalyzerDb) -> Option<AbiType> {
         let components = self
             .id
             .fields(db)
@@ -231,22 +231,22 @@ impl AsAbiType for Struct {
                     .as_abi_type(db)
             })
             .collect();
-        AbiType::Tuple { components }
+        Some(AbiType::Tuple { components })
     }
 }
 
 impl AsAbiType for Tuple {
-    fn as_abi_type(&self, db: &dyn AnalyzerDb) -> AbiType {
-        AbiType::Tuple {
+    fn as_abi_type(&self, db: &dyn AnalyzerDb) -> Option<AbiType> {
+        Some(AbiType::Tuple {
             components: self.items.iter().map(|typ| typ.as_abi_type(db)).collect(),
-        }
+        })
     }
 }
 
 impl AsAbiType for FeString {
-    fn as_abi_type(&self, _db: &dyn AnalyzerDb) -> AbiType {
-        AbiType::String {
+    fn as_abi_type(&self, _db: &dyn AnalyzerDb) -> Option<AbiType> {
+        Some(AbiType::String {
             max_size: self.max_size,
-        }
+        })
     }
 }