diff --git a/src/lune/builtins/fs/mod.rs b/src/lune/builtins/fs/mod.rs
index 7478118..0db1f7f 100644
--- a/src/lune/builtins/fs/mod.rs
+++ b/src/lune/builtins/fs/mod.rs
@@ -31,10 +31,10 @@ pub fn create(lua: &Lua) -> LuaResult<LuaTable> {
         .build_readonly()
 }
 
-async fn fs_read_file(lua: &Lua, path: String) -> LuaResult<LuaAnyUserData> {
+async fn fs_read_file(lua: &Lua, path: String) -> LuaResult<LuaString> {
     let bytes = fs::read(&path).await.into_lua_err()?;
 
-    lua.create_buffer(bytes)
+    lua.create_string(bytes)
 }
 
 async fn fs_read_dir(_: &Lua, path: String) -> LuaResult<Vec<String>> {
diff --git a/src/lune/builtins/serde/mod.rs b/src/lune/builtins/serde/mod.rs
index a5b267c..bad9f51 100644
--- a/src/lune/builtins/serde/mod.rs
+++ b/src/lune/builtins/serde/mod.rs
@@ -37,15 +37,15 @@ fn serde_decode<'lua>(
 async fn serde_compress<'lua>(
     lua: &'lua Lua,
     (format, str): (CompressDecompressFormat, BString),
-) -> LuaResult<LuaAnyUserData<'lua>> {
+) -> LuaResult<LuaString<'lua>> {
     let bytes = compress(format, str).await?;
-    lua.create_buffer(bytes)
+    lua.create_string(bytes)
 }
 
 async fn serde_decompress<'lua>(
     lua: &'lua Lua,
     (format, str): (CompressDecompressFormat, BString),
-) -> LuaResult<LuaAnyUserData<'lua>> {
+) -> LuaResult<LuaString<'lua>> {
     let bytes = decompress(format, str).await?;
-    lua.create_buffer(bytes)
+    lua.create_string(bytes)
 }