diff --git a/frontend/src/AddMovie/ImportMovie/Import/ImportMovie.js b/frontend/src/AddMovie/ImportMovie/Import/ImportMovie.js
index eb92afbdb3..70393d0528 100644
--- a/frontend/src/AddMovie/ImportMovie/Import/ImportMovie.js
+++ b/frontend/src/AddMovie/ImportMovie/Import/ImportMovie.js
@@ -50,7 +50,7 @@ class ImportMovie extends Component {
 
   onSelectAllChange = ({ value }) => {
     // Only select non-dupes
-    this.setState(selectAll(this.state.selectedState, value));
+    this.setState((prevState) => selectAll(prevState.selectedState, value));
   };
 
   onSelectedChange = ({ id, value, shiftKey = false }) => {
diff --git a/frontend/src/AddMovie/ImportMovie/Import/SelectMovie/ImportMovieSelectMovie.js b/frontend/src/AddMovie/ImportMovie/Import/SelectMovie/ImportMovieSelectMovie.js
index eca2eda874..fad7155ec6 100644
--- a/frontend/src/AddMovie/ImportMovie/Import/SelectMovie/ImportMovieSelectMovie.js
+++ b/frontend/src/AddMovie/ImportMovie/Import/SelectMovie/ImportMovieSelectMovie.js
@@ -78,7 +78,7 @@ class ImportMovieSelectMovie extends Component {
       this._addListener();
     }
 
-    this.setState({ isOpen: !this.state.isOpen });
+    this.setState((prevState) => ({ isOpen: !prevState.isOpen }));
   };
 
   onSearchInputChange = ({ value }) => {
diff --git a/frontend/src/Collection/Collection.js b/frontend/src/Collection/Collection.js
index 3430a2ed00..b8f8a2bae5 100644
--- a/frontend/src/Collection/Collection.js
+++ b/frontend/src/Collection/Collection.js
@@ -182,11 +182,13 @@ class Collection extends Component {
   };
 
   onSelectAllChange = ({ value }) => {
-    this.setState(selectAll(this.state.selectedState, value));
+    this.setState((prevState) => selectAll(prevState.selectedState, value));
   };
 
   onSelectAllPress = () => {
-    this.onSelectAllChange({ value: !this.state.allSelected });
+    this.setState((prevState) =>
+      selectAll(prevState.selectedState, !prevState.allSelected)
+    );
   };
 
   onRefreshMovieCollectionsPress = () => {
diff --git a/frontend/src/Components/Form/Select/QualityProfileSelectInput.tsx b/frontend/src/Components/Form/Select/QualityProfileSelectInput.tsx
index e4a844c7df..984fa0e29e 100644
--- a/frontend/src/Components/Form/Select/QualityProfileSelectInput.tsx
+++ b/frontend/src/Components/Form/Select/QualityProfileSelectInput.tsx
@@ -94,10 +94,7 @@ function QualityProfileSelectInput({
   );
 
   useEffect(() => {
-    if (
-      !value ||
-      !values.some((option) => option.key === value || option.key === value)
-    ) {
+    if (!value || !values.some((option) => option.key === value)) {
       const firstValue = values.find(
         (option) => typeof option.key === 'number'
       );
diff --git a/frontend/src/DiscoverMovie/DiscoverMovie.js b/frontend/src/DiscoverMovie/DiscoverMovie.js
index 8ec5c7badf..65dbada701 100644
--- a/frontend/src/DiscoverMovie/DiscoverMovie.js
+++ b/frontend/src/DiscoverMovie/DiscoverMovie.js
@@ -214,11 +214,13 @@ class DiscoverMovie extends Component {
   };
 
   onSelectAllChange = ({ value }) => {
-    this.setState(selectAll(this.state.selectedState, value));
+    this.setState((prevState) => selectAll(prevState.selectedState, value));
   };
 
   onSelectAllPress = () => {
-    this.onSelectAllChange({ value: !this.state.allSelected });
+    this.setState((prevState) =>
+      selectAll(prevState.selectedState, !prevState.allSelected)
+    );
   };
 
   onImportListSyncPress = () => {
diff --git a/frontend/src/Settings/Profiles/Quality/EditQualityProfileModalContentConnector.js b/frontend/src/Settings/Profiles/Quality/EditQualityProfileModalContentConnector.js
index bf6e3927e6..32126aabaf 100644
--- a/frontend/src/Settings/Profiles/Quality/EditQualityProfileModalContentConnector.js
+++ b/frontend/src/Settings/Profiles/Quality/EditQualityProfileModalContentConnector.js
@@ -474,7 +474,7 @@ class EditQualityProfileModalContentConnector extends Component {
   };
 
   onToggleEditGroupsMode = () => {
-    this.setState({ editGroups: !this.state.editGroups });
+    this.setState((prevState) => ({ editGroups: !prevState.editGroups }));
   };
 
   //
diff --git a/src/NzbDrone.SignalR/MessageHub.cs b/src/NzbDrone.SignalR/MessageHub.cs
index 9d0494e346..6f410d5f26 100644
--- a/src/NzbDrone.SignalR/MessageHub.cs
+++ b/src/NzbDrone.SignalR/MessageHub.cs
@@ -25,7 +25,7 @@ public async Task BroadcastMessage(SignalRMessage message)
 
     public class MessageHub : Hub
     {
-        private static HashSet<string> _connections = new HashSet<string>();
+        private static readonly HashSet<string> _connections = new HashSet<string>();
 
         public static bool IsConnected
         {