diff --git a/src/Xamarin.Android.Build.Tasks/Mono.Android/SupportsGLTextureAttribute.Partial.cs b/src/Xamarin.Android.Build.Tasks/Mono.Android/SupportsGLTextureAttribute.Partial.cs
index b632f1e4717..cd705268b73 100644
--- a/src/Xamarin.Android.Build.Tasks/Mono.Android/SupportsGLTextureAttribute.Partial.cs
+++ b/src/Xamarin.Android.Build.Tasks/Mono.Android/SupportsGLTextureAttribute.Partial.cs
@@ -12,7 +12,7 @@ namespace Android.App
 {
 	partial class SupportsGLTextureAttribute
 	{
-		static ManifestDocumentElement<SupportsGLTextureAttribute> mapping = new ManifestDocumentElement<SupportsGLTextureAttribute> ("supports-gl-texture") {
+		static readonly ManifestDocumentElement<SupportsGLTextureAttribute> mapping = new ManifestDocumentElement<SupportsGLTextureAttribute> ("supports-gl-texture") {
 			{
 			  "Name",
 			  "name",
diff --git a/src/Xamarin.Android.Build.Tasks/Tasks/Aapt2Link.cs b/src/Xamarin.Android.Build.Tasks/Tasks/Aapt2Link.cs
index 4785ecd12c5..c663a1d1603 100644
--- a/src/Xamarin.Android.Build.Tasks/Tasks/Aapt2Link.cs
+++ b/src/Xamarin.Android.Build.Tasks/Tasks/Aapt2Link.cs
@@ -20,7 +20,7 @@ namespace Xamarin.Android.Tasks {
 
 	//aapt2 link -o resources.apk.bk --manifest Foo.xml --java . --custom-package com.infinitespace_studios.blankforms -R foo2 -v --auto-add-overlay
 	public class Aapt2Link : Aapt2 {
-		static Regex exraArgSplitRegEx = new Regex (@"[\""].+?[\""]|[\''].+?[\'']|[^ ]+", RegexOptions.Compiled | RegexOptions.IgnoreCase | RegexOptions.Multiline);
+		static readonly Regex exraArgSplitRegEx = new Regex (@"[\""].+?[\""]|[\''].+?[\'']|[^ ]+", RegexOptions.Compiled | RegexOptions.IgnoreCase | RegexOptions.Multiline);
 		public override string TaskPrefix => "A2L";
 
 		[Required]
diff --git a/src/Xamarin.Android.Build.Tasks/Tasks/CheckForInvalidResourceFileNames.cs b/src/Xamarin.Android.Build.Tasks/Tasks/CheckForInvalidResourceFileNames.cs
index eef0fa9f85e..af44eabd506 100644
--- a/src/Xamarin.Android.Build.Tasks/Tasks/CheckForInvalidResourceFileNames.cs
+++ b/src/Xamarin.Android.Build.Tasks/Tasks/CheckForInvalidResourceFileNames.cs
@@ -24,7 +24,7 @@ public class CheckForInvalidResourceFileNames : AndroidTask {
 		Regex fileNameWithHyphenCheck = new Regex ("[^a-zA-Z0-9_.-]+", RegexOptions.Compiled);
 
 		// Source https://docs.oracle.com/javase/tutorial/java/nutsandbolts/_keywords.html
-		static string [] javaKeywords = {
+		static readonly string [] javaKeywords = {
 			"abstract",
 			"assert",
 			"boolean",
diff --git a/src/Xamarin.Android.Build.Tasks/Tasks/RemoveUnknownFiles.cs b/src/Xamarin.Android.Build.Tasks/Tasks/RemoveUnknownFiles.cs
index 83e3ec87661..9033ba4876d 100644
--- a/src/Xamarin.Android.Build.Tasks/Tasks/RemoveUnknownFiles.cs
+++ b/src/Xamarin.Android.Build.Tasks/Tasks/RemoveUnknownFiles.cs
@@ -14,7 +14,7 @@ public class RemoveUnknownFiles : AndroidTask
 	{
 		public override string TaskPrefix => "RUF";
 
-		static bool IsWindows = Path.DirectorySeparatorChar == '\\';
+		static readonly bool IsWindows = Path.DirectorySeparatorChar == '\\';
 
 		[Required]
 		public ITaskItem[] Files { get; set; } = [];
diff --git a/src/Xamarin.Android.Build.Tasks/Utilities/JavaObjectsXmlFile.cs b/src/Xamarin.Android.Build.Tasks/Utilities/JavaObjectsXmlFile.cs
index b9b51c4c1de..cfa39c669a7 100644
--- a/src/Xamarin.Android.Build.Tasks/Utilities/JavaObjectsXmlFile.cs
+++ b/src/Xamarin.Android.Build.Tasks/Utilities/JavaObjectsXmlFile.cs
@@ -13,7 +13,7 @@ namespace Xamarin.Android.Tasks;
 
 class JavaObjectsXmlFile
 {
-	static XmlWriterSettings settings = new XmlWriterSettings {
+	static readonly XmlWriterSettings settings = new XmlWriterSettings {
 		Indent = true,
 		NewLineOnAttributes = false,
 		OmitXmlDeclaration = true,
diff --git a/src/Xamarin.Android.Build.Tasks/Utilities/ManagedResourceParser.cs b/src/Xamarin.Android.Build.Tasks/Utilities/ManagedResourceParser.cs
index 68aa7e73423..0861e016444 100644
--- a/src/Xamarin.Android.Build.Tasks/Utilities/ManagedResourceParser.cs
+++ b/src/Xamarin.Android.Build.Tasks/Utilities/ManagedResourceParser.cs
@@ -35,7 +35,7 @@ public int Compare((int Key, CodeMemberField Value) x, (int Key, CodeMemberField
 		List<CodeTypeDeclaration> typeIds = new List<CodeTypeDeclaration> ();
 		Dictionary<CodeMemberField, CodeMemberField []> arrayMapping = new Dictionary<CodeMemberField, CodeMemberField []> ();
 		const string itemPackageId = "0x7f";
-		static CompareTuple compareTuple = new CompareTuple ();
+		static readonly CompareTuple compareTuple = new CompareTuple ();
 
 		XDocument publicXml;
 
diff --git a/src/Xamarin.Android.Build.Tasks/Utilities/ManifestDocument.cs b/src/Xamarin.Android.Build.Tasks/Utilities/ManifestDocument.cs
index 0ae414c812d..934bbe55206 100644
--- a/src/Xamarin.Android.Build.Tasks/Utilities/ManifestDocument.cs
+++ b/src/Xamarin.Android.Build.Tasks/Utilities/ManifestDocument.cs
@@ -31,13 +31,13 @@ namespace Xamarin.Android.Tasks {
 
 	internal class ManifestDocument
 	{
-		public static XNamespace AndroidXmlNamespace = "http://schemas.android.com/apk/res/android";
-		public static XNamespace AndroidXmlToolsNamespace = "http://schemas.android.com/tools";
+		public static readonly XNamespace AndroidXmlNamespace = "http://schemas.android.com/apk/res/android";
+		public static readonly XNamespace AndroidXmlToolsNamespace = "http://schemas.android.com/tools";
 
 		const int maxVersionCode = 2100000000;
 
-		static XNamespace androidNs = AndroidXmlNamespace;
-		static XNamespace androidToolsNs = AndroidXmlToolsNamespace;
+		static readonly XNamespace androidNs = AndroidXmlNamespace;
+		static readonly XNamespace androidToolsNs = AndroidXmlToolsNamespace;
 		static readonly XName versionCodeAttributeName = androidNs + "versionCode";
 
 		XDocument doc;
diff --git a/src/Xamarin.Android.Build.Tasks/Utilities/PathUtil.cs b/src/Xamarin.Android.Build.Tasks/Utilities/PathUtil.cs
index 5156ca8aa9a..7e0ac540c53 100644
--- a/src/Xamarin.Android.Build.Tasks/Utilities/PathUtil.cs
+++ b/src/Xamarin.Android.Build.Tasks/Utilities/PathUtil.cs
@@ -14,7 +14,7 @@ public static class PathUtil
 
 		internal const char VolumeSeparatorChar = ':';
 
-		static bool IsWindows = Path.DirectorySeparatorChar == '\\';
+		static readonly bool IsWindows = Path.DirectorySeparatorChar == '\\';
 		// Adapted from CoreFX sources
 		public static string GetRelativePath(string relativeTo, string path, StringComparison comparisonType = StringComparison.OrdinalIgnoreCase)
 		{
diff --git a/src/Xamarin.Android.Build.Tasks/Utilities/ResourceIdentifier.cs b/src/Xamarin.Android.Build.Tasks/Utilities/ResourceIdentifier.cs
index 7edfc38faf5..2a0c290f3e7 100644
--- a/src/Xamarin.Android.Build.Tasks/Utilities/ResourceIdentifier.cs
+++ b/src/Xamarin.Android.Build.Tasks/Utilities/ResourceIdentifier.cs
@@ -31,7 +31,7 @@ public class ResourceIdentifier {
 		private const string Identifier = IdentifierStartCharacter + "(" + IdentifierPartCharacter + ")";
 
 		// We use [^ ...] to detect any character that is NOT a match.
-		static Regex validIdentifier = new Regex ($"[^{Identifier}]", RegexOptions.Compiled);
+		static readonly Regex validIdentifier = new Regex ($"[^{Identifier}]", RegexOptions.Compiled);
 
 		public static string CreateValidIdentifier (string identifier)
 		{
diff --git a/src/Xamarin.Android.Build.Tasks/Utilities/RtxtParser.cs b/src/Xamarin.Android.Build.Tasks/Utilities/RtxtParser.cs
index c28e4b3fd95..81c7e97749d 100644
--- a/src/Xamarin.Android.Build.Tasks/Utilities/RtxtParser.cs
+++ b/src/Xamarin.Android.Build.Tasks/Utilities/RtxtParser.cs
@@ -71,7 +71,7 @@ public class RtxtParser {
 		TaskLoggingHelper? log;
 		Dictionary<string, string>? map;
 
-		public static HashSet<string> knownTypes = new HashSet<string> () {
+		public static readonly HashSet<string> knownTypes = new HashSet<string> () {
 			"anim",
 			"animator",
 			"attr",