diff --git a/src/qml/Chat/Banners/InviteBanner.qml b/src/qml/Chat/Banners/InviteBanner.qml
index 8f6621ed..4a8b7c34 100644
--- a/src/qml/Chat/Banners/InviteBanner.qml
+++ b/src/qml/Chat/Banners/InviteBanner.qml
@@ -35,18 +35,18 @@ Banner {
     ]
 
     buttonCallbacks: {
-        "accept": function(button) {
+        "accept": button => {
             button.loading = true
             py.callClientCoro(
-                chatPage.userId, "join", [chatPage.roomId], function() {
+                chatPage.userId, "join", [chatPage.roomId], () => {
                     button.loading = false
             })
         },
 
-        "decline": function(button) {
+        "decline": button => {
             button.loading = true
             py.callClientCoro(
-                chatPage.userId, "room_leave", [chatPage.roomId], function() {
+                chatPage.userId, "room_leave", [chatPage.roomId], () => {
                     button.loading = false
             })
         }
diff --git a/src/qml/Chat/Banners/LeftBanner.qml b/src/qml/Chat/Banners/LeftBanner.qml
index 43ab8465..00e0ab16 100644
--- a/src/qml/Chat/Banners/LeftBanner.qml
+++ b/src/qml/Chat/Banners/LeftBanner.qml
@@ -23,10 +23,10 @@ Banner {
     ]
 
     buttonCallbacks: {
-        "forget": function(button) {
+        "forget": button => {
             button.loading = true
             py.callClientCoro(
-                chatPage.userId, "room_forget", [chatPage.roomId], function() {
+                chatPage.userId, "room_forget", [chatPage.roomId], () => {
                     button.loading = false
             })
         }
diff --git a/src/qml/Chat/Banners/UnknownDevicesBanner.qml b/src/qml/Chat/Banners/UnknownDevicesBanner.qml
index de49c254..aee56546 100644
--- a/src/qml/Chat/Banners/UnknownDevicesBanner.qml
+++ b/src/qml/Chat/Banners/UnknownDevicesBanner.qml
@@ -21,8 +21,8 @@ Banner {
     ]
 
     buttonCallbacks: {
-        "inspect": function(button) {
+        "inspect": button => {
             print("show")
-        },
+        }
     }
 }
diff --git a/src/qml/Chat/Chat.qml b/src/qml/Chat/Chat.qml
index 9b763ab9..9d7d486e 100644
--- a/src/qml/Chat/Chat.qml
+++ b/src/qml/Chat/Chat.qml
@@ -107,7 +107,7 @@ HPage {
                 to: target.oldWidth
 
                 onStopped: target.Layout.minimumWidth = Qt.binding(
-                    function() { return theme.avatar.size }
+                    () => theme.avatar.size
                 )
            }
 
@@ -131,9 +131,7 @@ HPage {
                     currentWidth = referenceWidth
                     width = referenceWidth
                     wasSnapped = true
-                    currentWidth = Qt.binding(
-                        function() { return roomSidePane.width }
-                    )
+                    currentWidth = Qt.binding(() => roomSidePane.width)
                 } else {
                     wasSnapped = false
                 }
diff --git a/src/qml/Chat/Timeline/EventList.qml b/src/qml/Chat/Timeline/EventList.qml
index f5534b02..085ea97f 100644
--- a/src/qml/Chat/Timeline/EventList.qml
+++ b/src/qml/Chat/Timeline/EventList.qml
@@ -48,10 +48,8 @@ HRectangle {
                 print(canLoad, zz)
                 eventList.canLoad = false
                 py.callClientCoro(
-                    chatPage.userId,
-                    "load_past_events",
-                    [chatPage.roomId],
-                    function(more_to_load) { eventList.canLoad = more_to_load }
+                    chatPage.userId, "load_past_events", [chatPage.roomId],
+                    more_to_load => { eventList.canLoad = more_to_load }
                 )
             }
         }
diff --git a/src/qml/EventHandlers/rooms.js b/src/qml/EventHandlers/rooms.js
index c32e12c9..eb8b0aa5 100644
--- a/src/qml/EventHandlers/rooms.js
+++ b/src/qml/EventHandlers/rooms.js
@@ -14,7 +14,7 @@ function typingTextFor(members, our_user_id) {
         }
     }
 
-    profiles.sort(function(left, right) {
+    profiles.sort((left, right) => {
       if (left.displayName < right.displayName) { return -1 }
       if (left.displayName > right.displayName) { return +1 }
       return 0
diff --git a/src/qml/Pages/RememberAccount.qml b/src/qml/Pages/RememberAccount.qml
index e5ed148b..4a7c596a 100644
--- a/src/qml/Pages/RememberAccount.qml
+++ b/src/qml/Pages/RememberAccount.qml
@@ -22,11 +22,11 @@ Item {
         ]
 
         buttonCallbacks: {
-            "yes": function(button) {
+            "yes": button => {
                 py.callCoro("save_account", [userId])
                 pageStack.showPage("Default")
             },
-            "no": function(button) {
+            "no": button => {
                 py.callCoro("forget_account", [userId])
                 pageStack.showPage("Default")
             },
diff --git a/src/qml/Pages/SignIn.qml b/src/qml/Pages/SignIn.qml
index 7b7f7976..fc2f80ee 100644
--- a/src/qml/Pages/SignIn.qml
+++ b/src/qml/Pages/SignIn.qml
@@ -23,13 +23,13 @@ Item {
         ]
 
         buttonCallbacks: {
-            "register": function(button) {},
+            "register": button => {},
 
-            "login": function(button) {
+            "login": button => {
                 button.loading = true
                 var args = [idField.text, passwordField.text]
 
-                py.callCoro("login_client", args, function(user_id) {
+                py.callCoro("login_client", args, user_id => {
                     pageStack.showPage(
                         "RememberAccount",
                         {"loginWith": loginWith, "userId": user_id}
@@ -38,7 +38,7 @@ Item {
                 })
             },
 
-            "forgot": function(button) {}
+            "forgot": button => {}
         }
 
         HRowLayout {
diff --git a/src/qml/Python.qml b/src/qml/Python.qml
index 7ffe045e..9c90f981 100644
--- a/src/qml/Python.qml
+++ b/src/qml/Python.qml
@@ -42,17 +42,17 @@ Python {
 
         addImportPath("src")
         addImportPath("qrc:/")
-        importNames("python", ["APP"], function() {
-            call("APP.is_debug_on", [Qt.application.arguments], function(on) {
+        importNames("python", ["APP"], () => {
+            call("APP.is_debug_on", [Qt.application.arguments], on => {
                 window.debug = on
 
-                callCoro("has_saved_accounts", [], function(has) {
+                callCoro("has_saved_accounts", [], has => {
                     py.ready = true
                     willLoadAccounts(has)
 
                     if (has) {
                         py.loadingAccounts = true
-                        py.callCoro("load_saved_accounts", [], function() {
+                        py.callCoro("load_saved_accounts", [], () => {
                             py.loadingAccounts = false
                         })
                     }
diff --git a/src/qml/UI.qml b/src/qml/UI.qml
index f5f5bad1..0b41a6b9 100644
--- a/src/qml/UI.qml
+++ b/src/qml/UI.qml
@@ -13,9 +13,9 @@ Item {
 
     Connections {
         target: py
-        onWillLoadAccounts: function(will) {
+        onWillLoadAccounts: will => {
             pageStack.showPage(will ? "Default": "SignIn")
-            if (will) {initialRoomTimer.start()}
+            if (will) { initialRoomTimer.start() }
         }
     }
 
diff --git a/src/qml/utils.js b/src/qml/utils.js
index 0e88376c..ba4345a0 100644
--- a/src/qml/utils.js
+++ b/src/qml/utils.js
@@ -112,7 +112,7 @@ function filterMatches(filter, text) {
     var words = filter.split(" ")
 
     for (var i = 0; i < words.length; i++) {
-        if (words[i] && text.indexOf(words[i]) == -1) {
+        if (words[i] && ! text.includes(words[i])) {
             return false
         }
     }