diff --git a/src/event_loop/mod.rs b/src/event_loop/mod.rs
index fa749aab..0dad4ba8 100644
--- a/src/event_loop/mod.rs
+++ b/src/event_loop/mod.rs
@@ -170,6 +170,7 @@ mod test {
             im: InputMethod::Active(imdetails_new()),
             physical_keyboard: Presence::Missing,
             visibility_override: visibility::State::NotForced,
+            ..Application::new(start)
         };
         
         let l = State::new(state, now);
diff --git a/src/outputs.rs b/src/outputs.rs
index e82995bc..d04872b2 100644
--- a/src/outputs.rs
+++ b/src/outputs.rs
@@ -23,7 +23,7 @@ pub mod c {
     // Defined in C
 
     #[repr(transparent)]
-    #[derive(Clone, PartialEq, Copy, Debug)]
+    #[derive(Clone, PartialEq, Copy, Debug, Eq, Hash)]
     pub struct WlOutput(*const c_void);
 
     impl WlOutput {
@@ -382,7 +382,7 @@ impl OutputState {
 
 /// Not guaranteed to exist,
 /// but can be used to look up state.
-#[derive(Clone, Copy, PartialEq, Debug)]
+#[derive(Clone, Copy, PartialEq, Debug, Eq, Hash)]
 pub struct OutputId(c::WlOutput);
 
 // WlOutput is a pointer,
@@ -399,8 +399,10 @@ struct Output {
 #[derive(Debug)]
 struct NotFound;
 
+/// Wayland global ID type
 type GlobalId = u32;
 
+/// The outputs manager
 pub struct Outputs {
     outputs: Vec<(Output, GlobalId)>,
     sender: event_loop::driver::Threaded,
@@ -463,6 +465,6 @@ pub enum ChangeType {
 
 #[derive(Clone, Copy, Debug)]
 pub struct Event {
-    output: OutputId,
-    change: ChangeType,
+    pub output: OutputId,
+    pub change: ChangeType,
 }
diff --git a/src/state.rs b/src/state.rs
index 9009f1f4..f9bdcd8c 100644
--- a/src/state.rs
+++ b/src/state.rs
@@ -9,9 +9,10 @@ use crate::animation;
 use crate::imservice::{ ContentHint, ContentPurpose };
 use crate::main::{ Commands, PanelCommand };
 use crate::outputs;
+use crate::outputs::{OutputId, OutputState};
+use std::collections::HashMap;
 use std::time::Instant;
 
-
 #[derive(Clone, Copy)]
 pub enum Presence {
     Present,
@@ -139,6 +140,7 @@ pub struct Application {
     pub im: InputMethod,
     pub visibility_override: visibility::State,
     pub physical_keyboard: Presence,
+    pub outputs: HashMap<OutputId, OutputState>,
 }
 
 impl Application {
@@ -153,6 +155,7 @@ impl Application {
             im: InputMethod::InactiveSince(now),
             visibility_override: visibility::State::NotForced,
             physical_keyboard: Presence::Missing,
+            outputs: Default::default(),
         }
     }
 
@@ -173,9 +176,17 @@ impl Application {
                 ..self
             },
 
-            Event::Output(output) => {
-                println!("Stub: output event {:?}", output);
-                self
+            Event::Output(outputs::Event { output, change }) => {
+                let mut app = self;
+                match change {
+                    outputs::ChangeType::Altered(state) => {
+                        app.outputs.insert(output, state);
+                    },
+                    outputs::ChangeType::Removed => {
+                        app.outputs.remove(&output);
+                    },
+                };
+                app
             },
 
             Event::InputMethod(new_im) => match (self.im.clone(), new_im) {
@@ -271,6 +282,7 @@ mod test {
             im: InputMethod::Active(imdetails_new()),
             physical_keyboard: Presence::Missing,
             visibility_override: visibility::State::NotForced,
+            ..Application::new(start)
         };
 
         let state = state.apply_event(Event::InputMethod(InputMethod::InactiveSince(now)), now);
@@ -299,6 +311,7 @@ mod test {
             im: InputMethod::Active(imdetails_new()),
             physical_keyboard: Presence::Missing,
             visibility_override: visibility::State::NotForced,
+            ..Application::new(start)
         };
         
         let state = state.apply_event(Event::InputMethod(InputMethod::InactiveSince(now)), now);
@@ -323,6 +336,7 @@ mod test {
             im: InputMethod::Active(imdetails_new()),
             physical_keyboard: Presence::Missing,
             visibility_override: visibility::State::NotForced,
+            ..Application::new(start)
         };
         // This reflects the sequence from Wayland:
         // disable, disable, enable, disable
@@ -361,6 +375,7 @@ mod test {
             im: InputMethod::InactiveSince(now),
             physical_keyboard: Presence::Missing,
             visibility_override: visibility::State::NotForced,
+            ..Application::new(start)
         };
         now += Duration::from_secs(1);
 
@@ -394,6 +409,7 @@ mod test {
             im: InputMethod::Active(imdetails_new()),
             physical_keyboard: Presence::Missing,
             visibility_override: visibility::State::NotForced,
+            ..Application::new(start)
         };
         now += Duration::from_secs(1);