diff --git a/src/EditorFeatures/Core/Implementation/AutomaticCompletion/BraceCompletionSessionProvider.BraceCompletionSession.cs b/src/EditorFeatures/Core/Implementation/AutomaticCompletion/BraceCompletionSessionProvider.BraceCompletionSession.cs
index 46c211d4f8094..f3664ecaeb406 100644
--- a/src/EditorFeatures/Core/Implementation/AutomaticCompletion/BraceCompletionSessionProvider.BraceCompletionSession.cs
+++ b/src/EditorFeatures/Core/Implementation/AutomaticCompletion/BraceCompletionSessionProvider.BraceCompletionSession.cs
@@ -17,7 +17,6 @@
 using Microsoft.VisualStudio.Text.BraceCompletion;
 using Microsoft.VisualStudio.Text.Editor;
 using Microsoft.VisualStudio.Text.Operations;
-using Microsoft.VisualStudio.Utilities.Internal;
 using Roslyn.Utilities;
 
 namespace Microsoft.CodeAnalysis.Editor.Implementation.AutomaticCompletion
diff --git a/src/VisualStudio/Core/Def/Implementation/ChangeSignature/AddParameterDialogViewModel.cs b/src/VisualStudio/Core/Def/Implementation/ChangeSignature/AddParameterDialogViewModel.cs
index 70a5c03791bb0..adfe2d7dec0cb 100644
--- a/src/VisualStudio/Core/Def/Implementation/ChangeSignature/AddParameterDialogViewModel.cs
+++ b/src/VisualStudio/Core/Def/Implementation/ChangeSignature/AddParameterDialogViewModel.cs
@@ -10,7 +10,6 @@
 using Microsoft.CodeAnalysis.Notification;
 using Microsoft.CodeAnalysis.Shared.Extensions;
 using Microsoft.VisualStudio.LanguageServices.Implementation.Utilities;
-using Microsoft.VisualStudio.Utilities.Internal;
 using Roslyn.Utilities;
 
 namespace Microsoft.VisualStudio.LanguageServices.Implementation.ChangeSignature
@@ -141,13 +140,13 @@ internal bool CanSubmit([NotNullWhen(false)] out string? message)
                 return false;
             }
 
-            if (IsCallsiteRegularValue && CallSiteValue.IsNullOrWhiteSpace())
+            if (IsCallsiteRegularValue && string.IsNullOrWhiteSpace(CallSiteValue))
             {
                 message = ServicesVSResources.Enter_a_call_site_value_or_choose_a_different_value_injection_kind;
                 return false;
             }
 
-            if (IsOptional && DefaultValue.IsNullOrWhiteSpace())
+            if (IsOptional && string.IsNullOrWhiteSpace(DefaultValue))
             {
                 message = ServicesVSResources.Optional_parameters_must_provide_a_default_value;
                 return false;
@@ -177,7 +176,7 @@ private void SetCurrentTypeTextAndUpdateBindingStatus(string typeName)
         {
             VerbatimTypeName = typeName;
 
-            if (typeName.IsNullOrWhiteSpace())
+            if (string.IsNullOrWhiteSpace(typeName))
             {
                 TypeIsEmptyImage = Visibility.Visible;
                 TypeDoesNotParseImage = Visibility.Collapsed;
diff --git a/src/VisualStudio/Core/Def/Implementation/LanguageClient/InProcLanguageServer.cs b/src/VisualStudio/Core/Def/Implementation/LanguageClient/InProcLanguageServer.cs
index b207b9f173845..925f0564a011f 100644
--- a/src/VisualStudio/Core/Def/Implementation/LanguageClient/InProcLanguageServer.cs
+++ b/src/VisualStudio/Core/Def/Implementation/LanguageClient/InProcLanguageServer.cs
@@ -19,7 +19,6 @@
 using Microsoft.CodeAnalysis.Text;
 using Microsoft.VisualStudio.LanguageServer.Client;
 using Microsoft.VisualStudio.LanguageServer.Protocol;
-using Microsoft.VisualStudio.Utilities.Internal;
 using Roslyn.Utilities;
 using StreamJsonRpc;
 using LSP = Microsoft.VisualStudio.LanguageServer.Protocol;
@@ -558,7 +557,7 @@ internal async Task PublishDiagnosticsAsync(IDiagnosticService diagnosticService
                 {
                     // There were diagnostics from other documents, but none from the current document.
                     // If we're tracking the current document, we can stop.
-                    _publishedFileToDiagnostics.GetOrDefault(fileUri)?.Remove(document.Id);
+                    IReadOnlyDictionaryExtensions.GetValueOrDefault(_publishedFileToDiagnostics, fileUri)?.Remove(document.Id);
                     _documentsToPublishedUris.MultiRemove(document.Id, fileUri);
                 }
             }
@@ -644,8 +643,8 @@ private static LSP.DiagnosticSeverity Convert(CodeAnalysis.DiagnosticSeverity se
         // if we were working with a non-C#/VB file, then the property should have been populated.
         // In this case, unless we have a null client name, we don't want to publish the diagnostic
         // (since a null client name represents the C#/VB language server).
-        private bool IncludeDiagnostic(DiagnosticData diagnostic) =>
-            diagnostic.Properties.GetOrDefault(nameof(DocumentPropertiesService.DiagnosticsLspClientName)) == _clientName;
+        private bool IncludeDiagnostic(DiagnosticData diagnostic)
+            => IReadOnlyDictionaryExtensions.GetValueOrDefault(diagnostic.Properties, nameof(DocumentPropertiesService.DiagnosticsLspClientName)) == _clientName;
 
         private static LSP.Range GetDiagnosticRange(DiagnosticDataLocation diagnosticDataLocation, SourceText text)
         {