diff --git a/src/commands/audio_output_devices/disableoutput.rs b/src/commands/audio_output_devices/disableoutput.rs
index e86c236..54fc78c 100644
--- a/src/commands/audio_output_devices/disableoutput.rs
+++ b/src/commands/audio_output_devices/disableoutput.rs
@@ -20,10 +20,13 @@ impl Command for DisableOutput {
 
     fn parse_request(mut parts: RequestTokenizer<'_>) -> RequestParserResult<'_> {
         let output_id = parts.next().ok_or(RequestParserError::UnexpectedEOF)?;
+        let output_id = output_id
+            .parse()
+            .map_err(|_| RequestParserError::SyntaxError(0, output_id.to_owned()))?;
 
         debug_assert!(parts.next().is_none());
 
-        Ok((Request::DisableOutput(output_id.to_string()), ""))
+        Ok((Request::DisableOutput(output_id), ""))
     }
 
     fn parse_response(
diff --git a/src/commands/audio_output_devices/enableoutput.rs b/src/commands/audio_output_devices/enableoutput.rs
index 403f5d5..e8c45ab 100644
--- a/src/commands/audio_output_devices/enableoutput.rs
+++ b/src/commands/audio_output_devices/enableoutput.rs
@@ -20,10 +20,13 @@ impl Command for EnableOutput {
 
     fn parse_request(mut parts: RequestTokenizer<'_>) -> RequestParserResult<'_> {
         let output_id = parts.next().ok_or(RequestParserError::UnexpectedEOF)?;
+        let output_id = output_id
+            .parse()
+            .map_err(|_| RequestParserError::SyntaxError(0, output_id.to_owned()))?;
 
         debug_assert!(parts.next().is_none());
 
-        Ok((Request::EnableOutput(output_id.to_string()), ""))
+        Ok((Request::EnableOutput(output_id), ""))
     }
 
     fn parse_response(
diff --git a/src/commands/audio_output_devices/outputs.rs b/src/commands/audio_output_devices/outputs.rs
index dd1697d..37a9ab6 100644
--- a/src/commands/audio_output_devices/outputs.rs
+++ b/src/commands/audio_output_devices/outputs.rs
@@ -4,6 +4,7 @@ use serde::{Deserialize, Serialize};
 
 use crate::{
     commands::{Command, Request, RequestParserResult, ResponseParserError},
+    common::AudioOutputId,
     request_tokenizer::RequestTokenizer,
     response_tokenizer::{ResponseAttributes, expect_property_type},
 };
@@ -12,7 +13,7 @@ pub struct Outputs;
 
 #[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
 pub struct Output {
-    pub id: u64,
+    pub id: AudioOutputId,
     pub name: String,
     pub plugin: String,
     pub enabled: bool,
@@ -40,7 +41,7 @@ impl Command for Outputs {
     ) -> Result<Self::Response, ResponseParserError<'_>> {
         let mut outputs = Vec::new();
 
-        let mut id: Option<u64> = None;
+        let mut id: Option<AudioOutputId> = None;
         let mut name: Option<String> = None;
         let mut plugin: Option<String> = None;
         let mut enabled: Option<bool> = None;
@@ -64,7 +65,7 @@ impl Command for Outputs {
                     attributes = HashMap::new();
                     let id_s = expect_property_type!(Some(v), k, Text);
                     id = Some(
-                        id_s.parse::<u64>()
+                        id_s.parse()
                             .map_err(|_| ResponseParserError::SyntaxError(0, id_s))?,
                     );
                 }
diff --git a/src/commands/audio_output_devices/outputset.rs b/src/commands/audio_output_devices/outputset.rs
index e7b1a25..f595509 100644
--- a/src/commands/audio_output_devices/outputset.rs
+++ b/src/commands/audio_output_devices/outputset.rs
@@ -33,6 +33,9 @@ impl Command for OutputSet {
 
     fn parse_request(mut parts: RequestTokenizer<'_>) -> RequestParserResult<'_> {
         let output_id = parts.next().ok_or(RequestParserError::UnexpectedEOF)?;
+        let output_id = output_id
+            .parse()
+            .map_err(|_| RequestParserError::SyntaxError(0, output_id.to_owned()))?;
         let attribute_name = parts.next().ok_or(RequestParserError::UnexpectedEOF)?;
         let attribute_value = parts.next().ok_or(RequestParserError::UnexpectedEOF)?;
 
@@ -40,7 +43,7 @@ impl Command for OutputSet {
 
         Ok((
             Request::OutputSet(
-                output_id.to_string(),
+                output_id,
                 attribute_name.to_string(),
                 attribute_value.to_string(),
             ),
diff --git a/src/commands/audio_output_devices/toggleoutput.rs b/src/commands/audio_output_devices/toggleoutput.rs
index 89f4ed4..87d8ad8 100644
--- a/src/commands/audio_output_devices/toggleoutput.rs
+++ b/src/commands/audio_output_devices/toggleoutput.rs
@@ -20,10 +20,13 @@ impl Command for ToggleOutput {
 
     fn parse_request(mut parts: RequestTokenizer<'_>) -> RequestParserResult<'_> {
         let output_id = parts.next().ok_or(RequestParserError::UnexpectedEOF)?;
+        let output_id = output_id
+            .parse()
+            .map_err(|_| RequestParserError::SyntaxError(0, output_id.to_owned()))?;
 
         debug_assert!(parts.next().is_none());
 
-        Ok((Request::ToggleOutput(output_id.to_string()), ""))
+        Ok((Request::ToggleOutput(output_id), ""))
     }
 
     fn parse_response(
diff --git a/src/common/types.rs b/src/common/types.rs
index 7a36b7a..30b4e7b 100644
--- a/src/common/types.rs
+++ b/src/common/types.rs
@@ -30,6 +30,7 @@ pub use time_interval::TimeInterval;
 pub use volume_value::VolumeValue;
 pub use window_range::WindowRange;
 
+pub type AudioOutputId = u32;
 pub type Offset = u32;
 pub type PlaylistName = String;
 pub type PlaylistVersion = u32;
@@ -40,7 +41,6 @@ pub type SongPosition = u32;
 pub type TimeWithFractions = f64;
 
 // TODO: use a proper types
-pub type AudioOutputId = String;
 pub type Feature = String;
 pub type PartitionName = String;
 pub type Path = String;