diff --git a/.github/workflows/csv-coverage-pr-artifacts.yml b/.github/workflows/csv-coverage-pr-artifacts.yml
index 8e2df456260f..d9e0ccba5f29 100644
--- a/.github/workflows/csv-coverage-pr-artifacts.yml
+++ b/.github/workflows/csv-coverage-pr-artifacts.yml
@@ -44,7 +44,7 @@ jobs:
           git log -1 --format='%H'
         working-directory: base
       - name: Set up Python 3.8
-        uses: actions/setup-python@v4
+        uses: actions/setup-python@v5
         with:
           python-version: 3.8
       - name: Download CodeQL CLI
diff --git a/.github/workflows/csv-coverage-pr-comment.yml b/.github/workflows/csv-coverage-pr-comment.yml
index 86fe74d3419a..56904f261ba6 100644
--- a/.github/workflows/csv-coverage-pr-comment.yml
+++ b/.github/workflows/csv-coverage-pr-comment.yml
@@ -22,7 +22,7 @@ jobs:
     - name: Clone self (github/codeql)
       uses: actions/checkout@v4
     - name: Set up Python 3.8
-      uses: actions/setup-python@v4
+      uses: actions/setup-python@v5
       with:
         python-version: 3.8
 
diff --git a/.github/workflows/csv-coverage-timeseries.yml b/.github/workflows/csv-coverage-timeseries.yml
index cf2758dd9d34..2d7ef19465cd 100644
--- a/.github/workflows/csv-coverage-timeseries.yml
+++ b/.github/workflows/csv-coverage-timeseries.yml
@@ -18,7 +18,7 @@ jobs:
           path: codeqlModels
           fetch-depth: 0
       - name: Set up Python 3.8
-        uses: actions/setup-python@v4
+        uses: actions/setup-python@v5
         with:
           python-version: 3.8
       - name: Download CodeQL CLI
diff --git a/.github/workflows/csv-coverage-update.yml b/.github/workflows/csv-coverage-update.yml
index ccf1ffd47053..b1a6ccd32ee3 100644
--- a/.github/workflows/csv-coverage-update.yml
+++ b/.github/workflows/csv-coverage-update.yml
@@ -22,7 +22,7 @@ jobs:
           path: ql
           fetch-depth: 0
       - name: Set up Python 3.8
-        uses: actions/setup-python@v4
+        uses: actions/setup-python@v5
         with:
           python-version: 3.8
       - name: Download CodeQL CLI
diff --git a/.github/workflows/csv-coverage.yml b/.github/workflows/csv-coverage.yml
index 4fb1d143fc39..1498d5e699b3 100644
--- a/.github/workflows/csv-coverage.yml
+++ b/.github/workflows/csv-coverage.yml
@@ -22,7 +22,7 @@ jobs:
           path: codeqlModels
           ref: ${{ github.event.inputs.qlModelShaOverride || github.ref }}
       - name: Set up Python 3.8
-        uses: actions/setup-python@v4
+        uses: actions/setup-python@v5
         with:
           python-version: 3.8
       - name: Download CodeQL CLI
diff --git a/.github/workflows/query-list.yml b/.github/workflows/query-list.yml
index 07fb3b682da3..3a25fc90af0f 100644
--- a/.github/workflows/query-list.yml
+++ b/.github/workflows/query-list.yml
@@ -24,7 +24,7 @@ jobs:
       with:
         path: codeql 
     - name: Set up Python 3.8
-      uses: actions/setup-python@v4
+      uses: actions/setup-python@v5
       with:
         python-version: 3.8
     - name: Download CodeQL CLI
diff --git a/.github/workflows/swift.yml b/.github/workflows/swift.yml
index 8a04d4741181..c6cc23a1610b 100644
--- a/.github/workflows/swift.yml
+++ b/.github/workflows/swift.yml
@@ -79,7 +79,7 @@ jobs:
     steps:
       - uses: actions/checkout@v4
       - uses: bazelbuild/setup-bazelisk@v2
-      - uses: actions/setup-python@v4
+      - uses: actions/setup-python@v5
         with:
           python-version-file: 'swift/.python-version'
       - uses: pre-commit/action@v3.0.0
diff --git a/csharp/extractor/Semmle.Extraction.CSharp.StubGenerator/StubVisitor.cs b/csharp/extractor/Semmle.Extraction.CSharp.StubGenerator/StubVisitor.cs
index 57a1c823fc12..983175f4c17a 100644
--- a/csharp/extractor/Semmle.Extraction.CSharp.StubGenerator/StubVisitor.cs
+++ b/csharp/extractor/Semmle.Extraction.CSharp.StubGenerator/StubVisitor.cs
@@ -534,6 +534,9 @@ private void StubParameters(ICollection<IParameterSymbol> parameters)
                 case RefKind.In:
                     stubWriter.Write("in ");
                     break;
+                case RefKind.RefReadOnlyParameter:
+                    stubWriter.Write("ref readonly ");
+                    break;
                 default:
                     stubWriter.Write($"/* TODO: {parameter.RefKind} */");
                     break;
@@ -884,4 +887,4 @@ public override void VisitProperty(IPropertySymbol symbol)
         if (explicitInterfaceImplementations.Length == 0)
             StubProperty(symbol, null);
     }
-}
\ No newline at end of file
+}
diff --git a/csharp/extractor/Semmle.Extraction.Tests/StubGenerator.cs b/csharp/extractor/Semmle.Extraction.Tests/StubGenerator.cs
index 598ff77ca25b..ea60c60bad61 100644
--- a/csharp/extractor/Semmle.Extraction.Tests/StubGenerator.cs
+++ b/csharp/extractor/Semmle.Extraction.Tests/StubGenerator.cs
@@ -42,7 +42,7 @@ public void StubGeneratorMethodTest()
         // Setup
         const string source = @"
 public class MyTest {
-    public int M1(string arg1) { return 0;}
+    public int M1(string arg1) { return 0; }
 }";
 
         // Execute
@@ -56,6 +56,26 @@ public class MyTest {
         Assert.Equal(expected, stub);
     }
 
+    [Fact]
+    public void StubGeneratorRefReadonlyParameterTest()
+    {
+        // Setup
+        const string source = @"
+public class MyTest {
+    public int M1(ref readonly Guid guid) { return 0; }
+}";
+
+        // Execute
+        var stub = GenerateStub(source);
+
+        // Verify
+        const string expected = @"public class MyTest {
+public int M1(ref readonly Guid guid) => throw null;
+}
+";
+        Assert.Equal(expected, stub);
+    }
+
     private static string GenerateStub(string source)
     {
         var st = CSharpSyntaxTree.ParseText(source);