diff --git a/crates/wit/src/lib.rs b/crates/wit/src/lib.rs
index 3d098d4..96189c8 100644
--- a/crates/wit/src/lib.rs
+++ b/crates/wit/src/lib.rs
@@ -43,3 +43,4 @@ pub use parsed_type::ParsedType;
 pub use token_stream_generator::GENERATED_FUNC_PREFIX;
 pub use token_stream_generator::GENERATED_SECTION_PREFIX;
 pub use token_stream_generator::GENERATED_GLOBAL_PREFIX;
+pub use wasm_type::WasmType;
diff --git a/crates/wit/src/parse_macro_input/item_record.rs b/crates/wit/src/parse_macro_input/item_record.rs
index 05f022d..d88d9b2 100644
--- a/crates/wit/src/parse_macro_input/item_record.rs
+++ b/crates/wit/src/parse_macro_input/item_record.rs
@@ -13,6 +13,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
+
 use super::ParseMacroInput;
 use crate::{fce_ast_types, AstRecordField};
 use crate::fce_ast_types::FCEAst;
diff --git a/crates/wit/src/parsed_type.rs b/crates/wit/src/parsed_type.rs
index 88d0257..b36feae 100644
--- a/crates/wit/src/parsed_type.rs
+++ b/crates/wit/src/parsed_type.rs
@@ -21,6 +21,8 @@ mod foreign_mod_arg;
 mod foreign_mod_epilog;
 mod foreign_mod_prolog;
 
+use crate::wasm_type::WasmType;
+
 pub(crate) use fn_arg::*;
 pub(crate) use fn_epilog::*;
 pub(crate) use fn_prolog::*;
@@ -208,4 +210,22 @@ impl ParsedType {
             ParsedType::Utf8String | ParsedType::ByteVector | ParsedType::Record(_) => true,
         }
     }
+
+    pub fn to_raw_types(&self) -> Vec<WasmType> {
+        match self {
+            ParsedType::Boolean
+            | ParsedType::I8
+            | ParsedType::I16
+            | ParsedType::I32
+            | ParsedType::U8
+            | ParsedType::U16
+            | ParsedType::U32 => vec![WasmType::I32],
+            ParsedType::I64 | ParsedType::U64 => vec![WasmType::I64],
+            ParsedType::F32 => vec![WasmType::F32],
+            ParsedType::F64 => vec![WasmType::F64],
+            ParsedType::Utf8String | ParsedType::ByteVector | ParsedType::Record(_) => {
+                vec![WasmType::I32, WasmType::I32]
+            }
+        }
+    }
 }
diff --git a/crates/wit/src/parsed_type/fn_arg.rs b/crates/wit/src/parsed_type/fn_arg.rs
index 12b759c..4105438 100644
--- a/crates/wit/src/parsed_type/fn_arg.rs
+++ b/crates/wit/src/parsed_type/fn_arg.rs
@@ -1,3 +1,19 @@
+/*
+ * Copyright 2020 Fluence Labs Limited
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
 use super::ParsedType;
 use crate::wasm_type::WasmType;
 
@@ -8,21 +24,6 @@ pub(crate) trait FnArgGlueCodeGenerator {
 
 impl FnArgGlueCodeGenerator for ParsedType {
     fn generate_arguments(&self) -> Vec<WasmType> {
-        // TODO: investigate possible issues in conversion between signed and unsigned types
-        match self {
-            ParsedType::Boolean
-            | ParsedType::I8
-            | ParsedType::I16
-            | ParsedType::I32
-            | ParsedType::U8
-            | ParsedType::U16
-            | ParsedType::U32 => vec![WasmType::I32],
-            ParsedType::I64 | ParsedType::U64 => vec![WasmType::I64],
-            ParsedType::F32 => vec![WasmType::F32],
-            ParsedType::F64 => vec![WasmType::F64],
-            ParsedType::Utf8String | ParsedType::ByteVector | ParsedType::Record(_) => {
-                vec![WasmType::I32, WasmType::I32]
-            }
-        }
+        self.to_raw_types()
     }
 }
diff --git a/crates/wit/src/wasm_type.rs b/crates/wit/src/wasm_type.rs
index 9d7e1fc..652070c 100644
--- a/crates/wit/src/wasm_type.rs
+++ b/crates/wit/src/wasm_type.rs
@@ -1,7 +1,7 @@
 use proc_macro2::TokenStream;
 
 /// Raw Wasm types according to the spec except i128.
-pub(crate) enum WasmType {
+pub enum WasmType {
     I32,
     I64,
     F32,