diff --git a/paket.lock b/paket.lock
index 438445732..418bd46db 100644
--- a/paket.lock
+++ b/paket.lock
@@ -97,7 +97,7 @@ NUGET
       System.Collections.Immutable (>= 5.0)
       System.Reflection.Metadata (>= 5.0)
     Ionide.KeepAChangelog.Tasks (0.1.8) - copy_local: true
-    Ionide.LanguageServerProtocol (0.4.9)
+    Ionide.LanguageServerProtocol (0.4.10)
       FSharp.Core (>= 6.0)
       Newtonsoft.Json (>= 13.0.1)
       StreamJsonRpc (>= 2.10.44)
diff --git a/src/FsAutoComplete/CodeFixes.fs b/src/FsAutoComplete/CodeFixes.fs
index 12a57afd5..b6cde1051 100644
--- a/src/FsAutoComplete/CodeFixes.fs
+++ b/src/FsAutoComplete/CodeFixes.fs
@@ -310,7 +310,12 @@ module Run =
     runDiagnostics (fun d -> d.Message.Contains checkMessage) handler
 
   let ifDiagnosticByType (diagnosticType: string) handler : CodeFix =
-    runDiagnostics (fun d -> d.Source.Contains diagnosticType) handler
+    runDiagnostics
+      (fun d ->
+        match d.Source with
+        | None -> false
+        | Some s -> s.Contains diagnosticType)
+      handler
 
   let ifDiagnosticByCode codes handler : CodeFix =
     runDiagnostics (fun d -> d.Code.IsSome && Set.contains d.Code.Value codes) handler
diff --git a/src/FsAutoComplete/FsAutoComplete.Lsp.fs b/src/FsAutoComplete/FsAutoComplete.Lsp.fs
index ed98958bf..cb888bc23 100644
--- a/src/FsAutoComplete/FsAutoComplete.Lsp.fs
+++ b/src/FsAutoComplete/FsAutoComplete.Lsp.fs
@@ -400,7 +400,7 @@ type FSharpLspServer(state: State, lspClient: FSharpLspClient) =
             { Range = fcsRangeToLsp n
               Code = Some "FSAC0001"
               Severity = Some DiagnosticSeverity.Hint
-              Source = "FSAC"
+              Source = Some "FSAC"
               Message = "Unused open statement"
               RelatedInformation = None
               Tags = Some [| DiagnosticTag.Unnecessary |]
@@ -418,7 +418,7 @@ type FSharpLspServer(state: State, lspClient: FSharpLspClient) =
             { Range = fcsRangeToLsp n
               Code = Some "FSAC0003"
               Severity = Some DiagnosticSeverity.Hint
-              Source = "FSAC"
+              Source = Some "FSAC"
               Message = "This value is unused"
               RelatedInformation = Some [||]
               Tags = Some [| DiagnosticTag.Unnecessary |]
@@ -441,7 +441,7 @@ type FSharpLspServer(state: State, lspClient: FSharpLspClient) =
               { Diagnostic.Range = fcsRangeToLsp range
                 Code = Some "FSAC0002"
                 Severity = Some DiagnosticSeverity.Hint
-                Source = "FSAC"
+                Source = Some "FSAC"
                 Message = "This qualifier is redundant"
                 RelatedInformation = Some [||]
                 Tags = Some [| DiagnosticTag.Unnecessary |]
@@ -478,7 +478,7 @@ type FSharpLspServer(state: State, lspClient: FSharpLspClient) =
       //             { Range = range
       //               Code = Some w.Code
       //               Severity = Some DiagnosticSeverity.Information
-      //               Source = "F# Linter"
+      //               Source = Some "F# Linter"
       //               Message = w.Warning.Details.Message
       //               RelatedInformation = None
       //               Tags = None
@@ -524,7 +524,7 @@ type FSharpLspServer(state: State, lspClient: FSharpLspClient) =
               { Range = range
                 Code = Option.ofObj m.Code
                 Severity = Some severity
-                Source = $"F# Analyzers (%s{m.Type})"
+                Source = Some $"F# Analyzers (%s{m.Type})"
                 Message = m.Message
                 RelatedInformation = None
                 Tags = None
diff --git a/src/FsAutoComplete/LspHelpers.fs b/src/FsAutoComplete/LspHelpers.fs
index c7cef269f..707de3fe8 100644
--- a/src/FsAutoComplete/LspHelpers.fs
+++ b/src/FsAutoComplete/LspHelpers.fs
@@ -101,7 +101,7 @@ module Conversions =
             { Line = error.EndLine - 1
               Character = error.EndColumn } }
       Severity = fcsSeverityToDiagnostic error.Severity
-      Source = "F# Compiler"
+      Source = Some "F# Compiler"
       Message = error.Message
       Code = Some(string error.ErrorNumber)
       RelatedInformation = Some [||]
diff --git a/test/FsAutoComplete.Tests.Lsp/CompletionTests.fs b/test/FsAutoComplete.Tests.Lsp/CompletionTests.fs
index d5dfc0dc1..9553d3f58 100644
--- a/test/FsAutoComplete.Tests.Lsp/CompletionTests.fs
+++ b/test/FsAutoComplete.Tests.Lsp/CompletionTests.fs
@@ -428,11 +428,13 @@ let autoOpenTests state =
                      // Message required for QuickFix to fire ("is not defined")
                      Message = $"The value or constructor '{word}' is not defined."
                      Code = Some "39"
-                     Source = "F# Compiler"
+                     Source = Some "F# Compiler"
                      RelatedInformation = None
                      Tags = None
                      Data = None
-                     CodeDescription = None } |] } }
+                     CodeDescription = None } |]
+              Only = None
+              TriggerKind = None } }
 
       let (|ContainsOpenAction|_|) (codeActions: CodeAction []) =
         codeActions
diff --git a/test/FsAutoComplete.Tests.Lsp/ExtensionsTests.fs b/test/FsAutoComplete.Tests.Lsp/ExtensionsTests.fs
index d19a1e968..735d8be0e 100644
--- a/test/FsAutoComplete.Tests.Lsp/ExtensionsTests.fs
+++ b/test/FsAutoComplete.Tests.Lsp/ExtensionsTests.fs
@@ -116,7 +116,7 @@ let linterTests state =
              End = { Line = 0; Character = 11 } }
          Severity = Some DiagnosticSeverity.Information
          Code = Some "FL0042"
-         Source = "F# Linter"
+         Source = Some "F# Linter"
          Message = "Consider changing `test` to PascalCase."
          RelatedInformation = None
          Tags = None
@@ -128,7 +128,7 @@ let linterTests state =
              End = { Line = 1; Character = 25 } }
          Severity = Some DiagnosticSeverity.Information
          Code = Some "FL0065"
-         Source = "F# Linter"
+         Source = Some "F# Linter"
          Message = "`not (a = b)` might be able to be refactored into `a <> b`."
          RelatedInformation = None
          Tags = None
@@ -140,7 +140,7 @@ let linterTests state =
              End = { Line = 2; Character = 26 } }
          Severity = Some DiagnosticSeverity.Information
          Code = Some "FL0065"
-         Source = "F# Linter"
+         Source = Some "F# Linter"
          Message = "`not (a <> b)` might be able to be refactored into `a = b`."
          RelatedInformation = None
          Tags = None
@@ -152,7 +152,7 @@ let linterTests state =
              End = { Line = 3; Character = 22 } }
          Severity = Some DiagnosticSeverity.Information
          Code = Some "FL0065"
-         Source = "F# Linter"
+         Source = Some "F# Linter"
          Message = "`fun x -> x` might be able to be refactored into `id`."
          RelatedInformation = None
          Tags = None
@@ -164,7 +164,7 @@ let linterTests state =
              End = { Line = 4; Character = 20 } }
          Severity = Some DiagnosticSeverity.Information
          Code = Some "FL0065"
-         Source = "F# Linter"
+         Source = Some "F# Linter"
          Message = "`not true` might be able to be refactored into `false`."
          RelatedInformation = None
          Tags = None
@@ -176,7 +176,7 @@ let linterTests state =
              End = { Line = 5; Character = 21 } }
          Severity = Some DiagnosticSeverity.Information
          Code = Some "FL0065"
-         Source = "F# Linter"
+         Source = Some "F# Linter"
          Message = "`not false` might be able to be refactored into `true`."
          RelatedInformation = None
          Tags = None
@@ -188,7 +188,7 @@ let linterTests state =
              End = { Line = 7; Character = 21 } }
          Severity = Some DiagnosticSeverity.Information
          Code = Some "FL0065"
-         Source = "F# Linter"
+         Source = Some "F# Linter"
          Message = "`a <> true` might be able to be refactored into `not a`."
          RelatedInformation = None
          Tags = None
@@ -200,7 +200,7 @@ let linterTests state =
              End = { Line = 8; Character = 20 } }
          Severity = Some DiagnosticSeverity.Information
          Code = Some "FL0065"
-         Source = "F# Linter"
+         Source = Some "F# Linter"
          Message = "`x = null` might be able to be refactored into `isNull x`."
          RelatedInformation = None
          Tags = None
@@ -212,7 +212,7 @@ let linterTests state =
              End = { Line = 9; Character = 37 } }
          Severity = Some DiagnosticSeverity.Information
          Code = Some "FL0065"
-         Source = "F# Linter"
+         Source = Some "F# Linter"
          Message = "`List.head (List.sort x)` might be able to be refactored into `List.min x`."
          RelatedInformation = None
          Tags = None
@@ -343,7 +343,7 @@ let analyzerTests state =
                          End = { Line = 3; Character = 31 } }
                      Severity = Some DiagnosticSeverity.Warning
                      Code = Some "OV001"
-                     Source = "F# Analyzers (Option.Value analyzer)"
+                     Source = Some "F# Analyzers (Option.Value analyzer)"
                      Message = "Option.Value shouldn't be used"
                      RelatedInformation = None
                      Tags = None
diff --git a/test/FsAutoComplete.Tests.Lsp/Helpers.fs b/test/FsAutoComplete.Tests.Lsp/Helpers.fs
index 6451bdcf9..0ce6dfc90 100644
--- a/test/FsAutoComplete.Tests.Lsp/Helpers.fs
+++ b/test/FsAutoComplete.Tests.Lsp/Helpers.fs
@@ -559,10 +559,9 @@ let diagnosticsFromSource (desiredSource: String) =
   Observable.choose (fun (diags: Diagnostic[]) ->
     match diags
           |> Array.choose (fun d ->
-            if d.Source.StartsWith desiredSource then
-              Some d
-            else
-              None)
+            match d.Source with
+            | Some s -> if s.StartsWith desiredSource then Some d else None
+            | None -> None)
       with
     | [||] -> None
     | diags -> Some diags)
diff --git a/test/FsAutoComplete.Tests.Lsp/UnsedDeclarationsTests.fs b/test/FsAutoComplete.Tests.Lsp/UnsedDeclarationsTests.fs
index c6ce2c0e4..f0d5456b6 100644
--- a/test/FsAutoComplete.Tests.Lsp/UnsedDeclarationsTests.fs
+++ b/test/FsAutoComplete.Tests.Lsp/UnsedDeclarationsTests.fs
@@ -23,7 +23,7 @@ let private checkUsageAt
   expected
   = async {
     let source = sourceWithoutCursor |> Text.trimTripleQuotation
-    let! (doc, diags) = 
+    let! (doc, diags) =
       let getDoc =
         match doc with
         | Untitled -> Server.createUntitledDocument
@@ -36,7 +36,7 @@ let private checkUsageAt
       |> Array.filter (fun d -> d.Range |> Range.containsStrictly cursor)
 
     let isUnused (diag: Diagnostic) =
-      diag.Source = "FSAC"
+      diag.Source = Some "FSAC"
       &&
       diag.Code = Some "FSAC0003"
       &&
@@ -46,9 +46,9 @@ let private checkUsageAt
 
     let diag = diagsAtCursor |> Array.filter isUnused
     match expected with
-    | Unused -> 
+    | Unused ->
         Expect.hasLength diag 1 "There should be exactly one unused value diagnostic at cursor position"
-    | Used -> 
+    | Used ->
         Expect.hasLength diag 0 "There should be no unused value diagnostic at cursor position"
   }
 
@@ -59,12 +59,12 @@ let private checkUsage
   expected
   = async {
     let (cursor, source) =
-      sourceWithCursor 
+      sourceWithCursor
       |> Text.trimTripleQuotation
       |> Cursor.assertExtractPosition
     do! checkUsageAt server doc source cursor expected
   }
-  
+
 
 let private scriptTests state =
   let config = {
@@ -224,7 +224,7 @@ let private projectTests state =
         """
         Used
 
-    
+
     testCaseAsync "unused private function variable" <|
       checkUsage server file
         """
@@ -250,7 +250,7 @@ let private projectTests state =
         let $0f _ = ()
         """
         Used
-    
+
     // https://github.com/fsharp/FsAutoComplete/issues/832
     testList "issue #832" [
       // `$P`: used (or public -> not marked unused)
diff --git a/test/FsAutoComplete.Tests.Lsp/Utils/Server.fs b/test/FsAutoComplete.Tests.Lsp/Utils/Server.fs
index 5cb5733b6..4b61ffd94 100644
--- a/test/FsAutoComplete.Tests.Lsp/Utils/Server.fs
+++ b/test/FsAutoComplete.Tests.Lsp/Utils/Server.fs
@@ -377,7 +377,7 @@ module Document =
       let ps: CodeActionParams =
         { TextDocument = doc.TextDocumentIdentifier
           Range = range
-          Context = { Diagnostics = diagnostics } }
+          Context = { Diagnostics = diagnostics; Only = None; TriggerKind = None } }
 
       let! res = doc.Server.Server.TextDocumentCodeAction ps
       return res |> assertOk