diff --git a/src/GitVersionCore.Tests/NamedConfigFileLocatorTests.cs b/src/GitVersionCore.Tests/NamedConfigFileLocatorTests.cs
index 4331e9c062..df2cd36c3e 100644
--- a/src/GitVersionCore.Tests/NamedConfigFileLocatorTests.cs
+++ b/src/GitVersionCore.Tests/NamedConfigFileLocatorTests.cs
@@ -51,6 +51,37 @@ public void ThrowsExceptionOnAmbiguousConfigFileLocation()
             exception.Message.ShouldBe(expectedMessage);
         }
 
+        [Test]
+        public void DoNotThrowWhenWorkingAndRepoPathsAreSame()
+        {
+            workingPath = DefaultRepoPath;
+            SetupConfigFileContent(string.Empty, path: workingPath);
+
+            Should.NotThrow(() => { configFileLocator.Verify(workingPath, repoPath); });
+        }
+
+        [Test]
+        [Platform(Exclude = "Linux,Unix")]
+        public void DoNotThrowWhenWorkingAndRepoPathsAreSame_WithDifferentCasing()
+        {
+            workingPath = DefaultRepoPath.ToLower();
+            SetupConfigFileContent(string.Empty, path: workingPath);
+
+            Should.NotThrow(() => { configFileLocator.Verify(workingPath, repoPath); });
+        }
+
+        [Test]
+        public void DoNotThrowWhenConfigFileIsInSubDirectoryOfRepoPath()
+        {
+            workingPath = DefaultRepoPath;
+
+            options = Options.Create(new Arguments { ConfigFile = "./src/my-config.yaml" });
+            configFileLocator = new NamedConfigFileLocator(fileSystem, log, options);
+            SetupConfigFileContent(string.Empty, path: workingPath);
+
+            Should.NotThrow(() => { configFileLocator.Verify(workingPath, repoPath); });
+        }
+
         [Test]
         public void NoWarnOnCustomYmlFile()
         {
diff --git a/src/GitVersionCore.Tests/TestFileSystem.cs b/src/GitVersionCore.Tests/TestFileSystem.cs
index 2dff623698..95a0fac562 100644
--- a/src/GitVersionCore.Tests/TestFileSystem.cs
+++ b/src/GitVersionCore.Tests/TestFileSystem.cs
@@ -9,42 +9,49 @@ namespace GitVersionCore.Tests
 {
     public class TestFileSystem : IFileSystem
     {
-        private readonly Dictionary<string, byte[]> fileSystem = new Dictionary<string, byte[]>();
+        private static IEqualityComparer<string> fileSystemCasingComparer = System.Environment.OSVersion.Platform == PlatformID.Unix ? StringComparer.Ordinal : StringComparer.OrdinalIgnoreCase;
+        private readonly Dictionary<string, byte[]> fileSystem = new Dictionary<string, byte[]>(fileSystemCasingComparer);
 
         public void Copy(string @from, string to, bool overwrite)
         {
-            if (fileSystem.ContainsKey(to))
+            var fromPath = Path.GetFullPath(@from);
+            var toPath = Path.GetFullPath(to);
+            if (fileSystem.ContainsKey(toPath))
             {
                 if (overwrite)
-                    fileSystem.Remove(to);
+                    fileSystem.Remove(toPath);
                 else
                     throw new IOException("File already exists");
             }
 
-            if (!fileSystem.TryGetValue(from, out var source))
-                throw new FileNotFoundException($"The source file '{@from}' was not found", from);
+            if (!fileSystem.TryGetValue(fromPath, out var source))
+                throw new FileNotFoundException($"The source file '{fromPath}' was not found", from);
 
-            fileSystem.Add(to, source);
+            fileSystem.Add(toPath, source);
         }
 
         public void Move(string @from, string to)
         {
+            var fromPath = Path.GetFullPath(@from);
             Copy(from, to, false);
-            fileSystem.Remove(from);
+            fileSystem.Remove(fromPath);
         }
 
         public bool Exists(string file)
         {
-            return fileSystem.ContainsKey(file);
+            var path = Path.GetFullPath(file);
+            return fileSystem.ContainsKey(path);
         }
 
         public void Delete(string path)
         {
-            fileSystem.Remove(path);
+            var fullPath = Path.GetFullPath(path);
+            fileSystem.Remove(fullPath);
         }
 
-        public string ReadAllText(string path)
+        public string ReadAllText(string file)
         {
+            var path = Path.GetFullPath(file);
             if (!fileSystem.TryGetValue(path, out var content))
                 throw new FileNotFoundException($"The file '{path}' was not found", path);
 
@@ -54,15 +61,17 @@ public string ReadAllText(string path)
 
         public void WriteAllText(string file, string fileContents)
         {
-            var encoding = fileSystem.ContainsKey(file)
-                ? EncodingHelper.DetectEncoding(fileSystem[file]) ?? Encoding.UTF8
+            var path = Path.GetFullPath(file);
+            var encoding = fileSystem.ContainsKey(path)
+                ? EncodingHelper.DetectEncoding(fileSystem[path]) ?? Encoding.UTF8
                 : Encoding.UTF8;
-            WriteAllText(file, fileContents, encoding);
+            WriteAllText(path, fileContents, encoding);
         }
 
         public void WriteAllText(string file, string fileContents, Encoding encoding)
         {
-            fileSystem[file] = encoding.GetBytes(fileContents);
+            var path = Path.GetFullPath(file);
+            fileSystem[path] = encoding.GetBytes(fileContents);
         }
 
         public IEnumerable<string> DirectoryGetFiles(string directory, string searchPattern, SearchOption searchOption)
@@ -75,8 +84,9 @@ public Stream OpenWrite(string path)
             return new TestStream(path, this);
         }
 
-        public Stream OpenRead(string path)
+        public Stream OpenRead(string file)
         {
+            var path = Path.GetFullPath(file);
             if (fileSystem.ContainsKey(path))
             {
                 var content = fileSystem[path];
@@ -86,8 +96,9 @@ public Stream OpenRead(string path)
             throw new FileNotFoundException("File not found.", path);
         }
 
-        public void CreateDirectory(string path)
+        public void CreateDirectory(string directory)
         {
+            var path = Path.GetFullPath(directory);
             if (fileSystem.ContainsKey(path))
             {
                 fileSystem[path] = new byte[0];
@@ -98,8 +109,9 @@ public void CreateDirectory(string path)
             }
         }
 
-        public bool DirectoryExists(string path)
+        public bool DirectoryExists(string directory)
         {
+            var path = Path.GetFullPath(directory);
             return fileSystem.ContainsKey(path);
         }
 
diff --git a/src/GitVersionCore/Configuration/NamedConfigFileLocator.cs b/src/GitVersionCore/Configuration/NamedConfigFileLocator.cs
index 97faff0d44..09c994c502 100644
--- a/src/GitVersionCore/Configuration/NamedConfigFileLocator.cs
+++ b/src/GitVersionCore/Configuration/NamedConfigFileLocator.cs
@@ -36,6 +36,10 @@ private void WarnAboutAmbiguousConfigFileSelection(string workingDirectory, stri
             var workingConfigFile = GetConfigFilePath(workingDirectory);
             var projectRootConfigFile = GetConfigFilePath(projectRootDirectory);
 
+            var fileSystemCasingComparer = System.Environment.OSVersion.Platform == PlatformID.Unix ? StringComparison.Ordinal : StringComparison.OrdinalIgnoreCase;
+            if (Path.GetFullPath(workingConfigFile).Equals(Path.GetFullPath(projectRootConfigFile), fileSystemCasingComparer))
+                return;
+
             var hasConfigInWorkingDirectory = FileSystem.Exists(workingConfigFile);
             var hasConfigInProjectRootDirectory = FileSystem.Exists(projectRootConfigFile);
             if (hasConfigInProjectRootDirectory && hasConfigInWorkingDirectory)