diff --git a/src/Meziantou.Analyzer/Internals/AwaitableTypes.cs b/src/Meziantou.Analyzer/Internals/AwaitableTypes.cs
index e12affd5..4367fc39 100644
--- a/src/Meziantou.Analyzer/Internals/AwaitableTypes.cs
+++ b/src/Meziantou.Analyzer/Internals/AwaitableTypes.cs
@@ -7,6 +7,7 @@ namespace Meziantou.Analyzer.Internals;
 internal sealed class AwaitableTypes
 {
     private readonly INamedTypeSymbol[] _taskOrValueTaskSymbols;
+    private readonly Compilation _compilation;
 
     public AwaitableTypes(Compilation compilation)
     {
@@ -30,6 +31,8 @@ public AwaitableTypes(Compilation compilation)
         {
             _taskOrValueTaskSymbols = [];
         }
+
+        _compilation = compilation;
     }
 
     private INamedTypeSymbol? TaskSymbol { get; }
@@ -74,7 +77,7 @@ public bool IsAwaitable(ITypeSymbol? symbol, SemanticModel semanticModel, int po
         return false;
     }
 
-    public bool IsAwaitable(ITypeSymbol? symbol, Compilation compilation)
+    public bool IsAwaitable(ITypeSymbol? symbol)
     {
         if (symbol is null)
             return false;
@@ -95,7 +98,7 @@ public bool IsAwaitable(ITypeSymbol? symbol, Compilation compilation)
             if (potentialSymbol is not IMethodSymbol getAwaiterMethod)
                 continue;
 
-            if (!compilation.IsSymbolAccessibleWithin(potentialSymbol, compilation.Assembly))
+            if (!_compilation.IsSymbolAccessibleWithin(potentialSymbol, _compilation.Assembly))
                 continue;
 
             if (!getAwaiterMethod.Parameters.IsEmpty)
diff --git a/src/Meziantou.Analyzer/Rules/MethodsReturningAnAwaitableTypeMustHaveTheAsyncSuffixAnalyzer.cs b/src/Meziantou.Analyzer/Rules/MethodsReturningAnAwaitableTypeMustHaveTheAsyncSuffixAnalyzer.cs
index fec78c89..e574dcb1 100644
--- a/src/Meziantou.Analyzer/Rules/MethodsReturningAnAwaitableTypeMustHaveTheAsyncSuffixAnalyzer.cs
+++ b/src/Meziantou.Analyzer/Rules/MethodsReturningAnAwaitableTypeMustHaveTheAsyncSuffixAnalyzer.cs
@@ -86,7 +86,7 @@ public void AnalyzeSymbol(SymbolAnalysisContext context)
                 return;
 
             var hasAsyncSuffix = method.Name.EndsWith("Async", StringComparison.Ordinal);
-            if (_awaitableTypes.IsAwaitable(method.ReturnType, context.Compilation))
+            if (_awaitableTypes.IsAwaitable(method.ReturnType))
             {
                 if (!hasAsyncSuffix)
                 {
@@ -119,7 +119,7 @@ public void AnalyzeLocalFunction(OperationAnalysisContext context)
             var method = operation.Symbol;
 
             var hasAsyncSuffix = method.Name.EndsWith("Async", StringComparison.Ordinal);
-            if (_awaitableTypes.IsAwaitable(method.ReturnType, context.Compilation))
+            if (_awaitableTypes.IsAwaitable(method.ReturnType))
             {
                 if (!hasAsyncSuffix)
                 {
diff --git a/src/Meziantou.Analyzer/Rules/UseStringComparerAnalyzer.cs b/src/Meziantou.Analyzer/Rules/UseStringComparerAnalyzer.cs
index a9e14483..127949af 100644
--- a/src/Meziantou.Analyzer/Rules/UseStringComparerAnalyzer.cs
+++ b/src/Meziantou.Analyzer/Rules/UseStringComparerAnalyzer.cs
@@ -1,4 +1,4 @@
-using System;
+using System;
 using System.Collections.Generic;
 using System.Collections.Immutable;
 using System.Linq;
@@ -77,6 +77,8 @@ private sealed class AnalyzerContext(Compilation compilation)
         public INamedTypeSymbol? ComparerStringType { get; } = GetIComparerString(compilation);
         public INamedTypeSymbol? EnumerableType { get; } = compilation.GetBestTypeByMetadataName("System.Linq.Enumerable");
         public INamedTypeSymbol? ISetType { get; } = compilation.GetBestTypeByMetadataName("System.Collections.Generic.ISet`1")?.Construct(compilation.GetSpecialType(SpecialType.System_String));
+        public INamedTypeSymbol? IReadOnlySetType { get; } = compilation.GetBestTypeByMetadataName("System.Collections.Generic.IReadOnlySet`1")?.Construct(compilation.GetSpecialType(SpecialType.System_String));
+        public INamedTypeSymbol? IImmutableSetType { get; } = compilation.GetBestTypeByMetadataName("System.Collections.Immutable.IImmutableSet`1")?.Construct(compilation.GetSpecialType(SpecialType.System_String));
 
         public void AnalyzeConstructor(OperationAnalysisContext ctx)
         {
@@ -109,11 +111,18 @@ public void AnalyzeInvocation(OperationAnalysisContext ctx)
             // Most ISet implementation already configured the IEqualityComparer in this constructor,
             // so it should be ok to skip method calls on those types.
             // A concrete use-case is HashSet<string>.Contains which has an extension method IEnumerable.Contains(value, comparer)
-            if (ISetType is not null && method.ContainingType.IsOrImplements(ISetType))
-                return;
+            foreach (var type in (ReadOnlySpan<ITypeSymbol?>)[ISetType, IReadOnlySetType, IImmutableSetType])
+            {
 
-            if (operation.Instance is not null && operation.Instance.GetActualType()?.IsOrImplements(ISetType) == true)
-                return;
+                if (type is null)
+                    continue;
+
+                if (method.ContainingType.IsOrImplements(type))
+                    return;
+
+                if (operation.Instance is not null && operation.Instance.GetActualType()?.IsOrImplements(type) is true)
+                    return;
+            }
 
             if (operation.IsImplicit && IsQueryOperator(operation) && ctx.Options.GetConfigurationValue(operation, Rule.Id + ".exclude_query_operator_syntaxes", defaultValue: false))
                 return;
diff --git a/tests/Meziantou.Analyzer.Test/Helpers/ProjectBuilder.Validation.cs b/tests/Meziantou.Analyzer.Test/Helpers/ProjectBuilder.Validation.cs
index 08485a46..94c1cfcf 100755
--- a/tests/Meziantou.Analyzer.Test/Helpers/ProjectBuilder.Validation.cs
+++ b/tests/Meziantou.Analyzer.Test/Helpers/ProjectBuilder.Validation.cs
@@ -1,4 +1,4 @@
-using System;
+using System;
 using System.Collections.Generic;
 using System.Collections.Immutable;
 using System.Diagnostics;
@@ -219,10 +219,10 @@ private Task<Project> CreateProject()
                 break;
         }
 
-        AddNuGetReference("System.Collections.Immutable", "1.5.0", "lib/netstandard2.0/");
 
         if (TargetFramework is not TargetFramework.Net7_0 and not TargetFramework.Net8_0 and not TargetFramework.Net9_0)
         {
+            AddNuGetReference("System.Collections.Immutable", "1.5.0", "lib/netstandard2.0/");
             AddNuGetReference("System.Numerics.Vectors", "4.5.0", "ref/netstandard2.0/");
         }
 
diff --git a/tests/Meziantou.Analyzer.Test/Rules/UseStringComparerAnalyzerTests.cs b/tests/Meziantou.Analyzer.Test/Rules/UseStringComparerAnalyzerTests.cs
index 14ca7c3b..049d0602 100755
--- a/tests/Meziantou.Analyzer.Test/Rules/UseStringComparerAnalyzerTests.cs
+++ b/tests/Meziantou.Analyzer.Test/Rules/UseStringComparerAnalyzerTests.cs
@@ -1,4 +1,4 @@
-using System.Threading.Tasks;
+using System.Threading.Tasks;
 using Meziantou.Analyzer.Rules;
 using Meziantou.Analyzer.Test.Helpers;
 using TestHelper;
@@ -458,6 +458,48 @@ await CreateProjectBuilder()
               .ValidateAsync();
     }
 
+    [Fact]
+    public async Task IReadOnlySet_Contain()
+    {
+        const string SourceCode = """
+            using System.Linq;
+            class TypeName
+            {
+                public void Test()
+                {
+                    System.Collections.Generic.IReadOnlySet<string> obj = null;
+                    obj.Contains("");
+                }
+            }
+            """;
+
+        await CreateProjectBuilder()
+              .WithTargetFramework(TargetFramework.Net6_0)
+              .WithSourceCode(SourceCode)
+              .ValidateAsync();
+    }
+
+    [Fact]
+    public async Task IImmutableSet_Contain()
+    {
+        const string SourceCode = """
+            using System.Linq;
+            class TypeName
+            {
+                public void Test()
+                {
+                    System.Collections.Immutable.IImmutableSet<string> obj = null;
+                    obj.Contains("");
+                }
+            }
+            """;
+
+        await CreateProjectBuilder()
+              .WithTargetFramework(TargetFramework.Net9_0)
+              .WithSourceCode(SourceCode)
+              .ValidateAsync();
+    }
+
     [Fact]
     public async Task StringArray_QuerySyntax_GroupBy_NoConfiguration()
     {