diff --git a/Ramstack.Globbing/Internal/PathHelper.cs b/Ramstack.Globbing/Internal/PathHelper.cs
index a03a128..33b1aa7 100644
--- a/Ramstack.Globbing/Internal/PathHelper.cs
+++ b/Ramstack.Globbing/Internal/PathHelper.cs
@@ -21,13 +21,17 @@ internal static class PathHelper
     /// </summary>
     /// <param name="path">The path to match for a match.</param>
     /// <param name="patterns">An array of patterns to match against the path.</param>
-    /// <param name="flags">The matching options to use.</param>
+    /// <param name="flags">The matching options to use.
+    /// This parameter must be explicitly set to either <see cref="MatchFlags.Windows"/> or <see cref="MatchFlags.Unix"/>.
+    /// <see cref="MatchFlags.Auto"/> is not allowed and will result in an assertion failure.</param>
     /// <returns>
     /// <see langword="true" /> if the path matches any of the patterns;
     /// otherwise, <see langword="false" />.
     /// </returns>
     public static bool IsMatch(ReadOnlySpan<char> path, string[] patterns, MatchFlags flags)
     {
+        Debug.Assert(flags != MatchFlags.Auto);
+
         foreach (var pattern in patterns)
             if (Matcher.IsMatch(path, pattern, flags))
                 return true;
@@ -40,13 +44,17 @@ public static bool IsMatch(ReadOnlySpan<char> path, string[] patterns, MatchFlag
     /// </summary>
     /// <param name="path">The path to be partially matched.</param>
     /// <param name="patterns">An array of patterns to match against the path.</param>
-    /// <param name="flags">The matching options to use.</param>
+    /// <param name="flags">The matching options to use.
+    /// This parameter must be explicitly set to either <see cref="MatchFlags.Windows"/> or <see cref="MatchFlags.Unix"/>.
+    /// <see cref="MatchFlags.Auto"/> is not allowed and will result in an assertion failure.</param>
     /// <returns>
     /// <see langword="true" /> if the path partially matches any of the patterns;
     /// otherwise, <see langword="false" />.
     /// </returns>
     public static bool IsPartialMatch(ReadOnlySpan<char> path, string[] patterns, MatchFlags flags)
     {
+        Debug.Assert(flags != MatchFlags.Auto);
+
         var count = CountPathSegments(path, flags);
 
         foreach (var pattern in patterns)
@@ -60,12 +68,16 @@ public static bool IsPartialMatch(ReadOnlySpan<char> path, string[] patterns, Ma
     /// Counts the number of segments in the specified path.
     /// </summary>
     /// <param name="path">The path to count segments for.</param>
-    /// <param name="flags">The flags indicating the type of path separators to match.</param>
+    /// <param name="flags">The flags indicating the type of path separators to match.
+    /// This parameter must be explicitly set to either <see cref="MatchFlags.Windows"/> or <see cref="MatchFlags.Unix"/>.
+    /// <see cref="MatchFlags.Auto"/> is not allowed and will result in an assertion failure.</param>
     /// <returns>
     /// The number of segments in the path.
     /// </returns>
     public static int CountPathSegments(scoped ReadOnlySpan<char> path, MatchFlags flags)
     {
+        Debug.Assert(flags != MatchFlags.Auto);
+
         var count = 0;
         var iterator = new PathSegmentIterator();
         ref var s = ref Unsafe.AsRef(in MemoryMarshal.GetReference(path));
@@ -92,13 +104,16 @@ public static int CountPathSegments(scoped ReadOnlySpan<char> path, MatchFlags f
     /// Returns a partial pattern from the specified pattern string based on the specified depth.
     /// </summary>
     /// <param name="pattern">The pattern string to extract from.</param>
-    /// <param name="flags">The flags indicating the type of path separators to match.</param>
+    /// <param name="flags">The flags indicating the type of path separators to match.
+    /// This parameter must be explicitly set to either <see cref="MatchFlags.Windows"/> or <see cref="MatchFlags.Unix"/>.
+    /// <see cref="MatchFlags.Auto"/> is not allowed and will result in an assertion failure.</param>
     /// <param name="depth">The depth level to extract the partial pattern up to.</param>
     /// <returns>
     /// A <see cref="ReadOnlySpan{T}"/> representing the partial pattern.
     /// </returns>
     public static ReadOnlySpan<char> GetPartialPattern(string pattern, MatchFlags flags, int depth)
     {
+        Debug.Assert(flags != MatchFlags.Auto);
         Debug.Assert(depth >= 1);
 
         if (depth < 1)
@@ -227,12 +242,16 @@ static void ConvertPathToPosixStyleImpl(ref char p, nint length)
     /// <summary>
     /// Creates a 256-bit bitmask that allows escaping characters based on the specified flags.
     /// </summary>
-    /// <param name="flags">The flags indicating the type of path separators to match.</param>
+    /// <param name="flags">The flags indicating the type of path separators to match.
+    /// This parameter must be explicitly set to either <see cref="MatchFlags.Windows"/> or <see cref="MatchFlags.Unix"/>.
+    /// <see cref="MatchFlags.Auto"/> is not allowed and will result in an assertion failure.</param>
     /// <returns>
     /// A 256-bit bitmask for escaping characters.
     /// </returns>
     private static Vector256<ushort> CreateBackslash256Bitmask(MatchFlags flags)
     {
+        Debug.Assert(flags != MatchFlags.Auto);
+
         var mask = Vector256<ushort>.Zero;
         if (flags == MatchFlags.Windows)
             mask = Vector256<ushort>.AllBitsSet;
@@ -243,12 +262,16 @@ private static Vector256<ushort> CreateBackslash256Bitmask(MatchFlags flags)
     /// <summary>
     /// Creates a 128-bit bitmask that allows escaping characters based on the specified flags.
     /// </summary>
-    /// <param name="flags">The flags indicating the type of path separators to match.</param>
+    /// <param name="flags">The flags indicating the type of path separators to match.
+    /// This parameter must be explicitly set to either <see cref="MatchFlags.Windows"/> or <see cref="MatchFlags.Unix"/>.
+    /// <see cref="MatchFlags.Auto"/> is not allowed and will result in an assertion failure.</param>
     /// <returns>
     /// A 128-bit bitmask for escaping characters.
     /// </returns>
     private static Vector128<ushort> CreateBackslash128Bitmask(MatchFlags flags)
     {
+        Debug.Assert(flags != MatchFlags.Auto);
+
         var mask = Vector128<ushort>.Zero;
         if (flags == MatchFlags.Windows)
             mask = Vector128<ushort>.AllBitsSet;
diff --git a/Ramstack.Globbing/Traversal/DirectoryInfoExtensions.cs b/Ramstack.Globbing/Traversal/DirectoryInfoExtensions.cs
index c8ed791..d2a8b87 100644
--- a/Ramstack.Globbing/Traversal/DirectoryInfoExtensions.cs
+++ b/Ramstack.Globbing/Traversal/DirectoryInfoExtensions.cs
@@ -753,7 +753,7 @@ public static IEnumerable<FileSystemInfo> EnumerateFileSystemInfos(this Director
 
     private static IEnumerable<FileInfo> EnumerateFiles(string path, string[] patterns, string[] excludes, MatchFlags flags, SearchTarget target, EnumerationOptions options)
     {
-        flags = Files.AdjustMatchFlags(flags);
+        flags = Files.ResolveMatchFlags(flags);
 
         return new FileSystemEnumerable<FileInfo>(path, (ref entry) => (FileInfo)entry.ToFileSystemInfo(), options)
         {
@@ -764,7 +764,7 @@ private static IEnumerable<FileInfo> EnumerateFiles(string path, string[] patter
 
     private static IEnumerable<DirectoryInfo> EnumerateDirectories(string path, string[] patterns, string[] excludes, MatchFlags flags, SearchTarget target, EnumerationOptions options)
     {
-        flags = Files.AdjustMatchFlags(flags);
+        flags = Files.ResolveMatchFlags(flags);
 
         return new FileSystemEnumerable<DirectoryInfo>(path, (ref entry) => (DirectoryInfo)entry.ToFileSystemInfo(), options)
         {
@@ -775,7 +775,7 @@ private static IEnumerable<DirectoryInfo> EnumerateDirectories(string path, stri
 
     private static IEnumerable<FileSystemInfo> EnumerateInfos(string path, string[] patterns, string[] excludes, MatchFlags flags, SearchTarget target, EnumerationOptions options)
     {
-        flags = Files.AdjustMatchFlags(flags);
+        flags = Files.ResolveMatchFlags(flags);
 
         return new FileSystemEnumerable<FileSystemInfo>(path, (ref entry) => entry.ToFileSystemInfo(), options)
         {
diff --git a/Ramstack.Globbing/Traversal/FileTreeAsyncEnumerable.cs b/Ramstack.Globbing/Traversal/FileTreeAsyncEnumerable.cs
index bb1f977..d026261 100644
--- a/Ramstack.Globbing/Traversal/FileTreeAsyncEnumerable.cs
+++ b/Ramstack.Globbing/Traversal/FileTreeAsyncEnumerable.cs
@@ -86,6 +86,7 @@ private async IAsyncEnumerable<TResult> EnumerateAsync(CancellationTokenSource?
     {
         try
         {
+            var flags = Files.ResolveMatchFlags(Flags);
             var chars = ArrayPool<char>.Shared.Rent(FileTreeEnumerable<TEntry, TResult>.DefaultBufferCapacity);
 
             var queue = new Queue<(TEntry Directory, string Path)>();
@@ -98,15 +99,15 @@ private async IAsyncEnumerable<TResult> EnumerateAsync(CancellationTokenSource?
                     var name = FileNameSelector(entry);
                     var fullName = FileTreeHelper.GetFullName(ref chars, e.Path, name);
 
-                    if (PathHelper.IsMatch(fullName, Excludes, Flags))
+                    if (PathHelper.IsMatch(fullName, Excludes, flags))
                         continue;
 
                     if (ShouldRecursePredicate == null || ShouldRecursePredicate(entry))
-                        if (PathHelper.IsPartialMatch(fullName, Patterns, Flags))
+                        if (PathHelper.IsPartialMatch(fullName, Patterns, flags))
                             queue.Enqueue((entry, fullName.ToString()));
 
                     if (ShouldIncludePredicate == null || ShouldIncludePredicate(entry))
-                        if (PathHelper.IsMatch(fullName, Patterns, Flags))
+                        if (PathHelper.IsMatch(fullName, Patterns, flags))
                             yield return ResultSelector(entry);
                 }
             }
diff --git a/Ramstack.Globbing/Traversal/FileTreeEnumerable.cs b/Ramstack.Globbing/Traversal/FileTreeEnumerable.cs
index eb907b4..41f5643 100644
--- a/Ramstack.Globbing/Traversal/FileTreeEnumerable.cs
+++ b/Ramstack.Globbing/Traversal/FileTreeEnumerable.cs
@@ -77,8 +77,8 @@ IEnumerator IEnumerable.GetEnumerator() =>
 
     private IEnumerable<TResult> Enumerate()
     {
+        var flags = Files.ResolveMatchFlags(Flags);
         var chars = ArrayPool<char>.Shared.Rent(DefaultBufferCapacity);
-
         var queue = new Queue<(TEntry Directory, string Path)>();
         queue.Enqueue((_directory, ""));
 
@@ -89,15 +89,15 @@ private IEnumerable<TResult> Enumerate()
                 var name = FileNameSelector(entry);
                 var fullName = FileTreeHelper.GetFullName(ref chars, e.Path, name);
 
-                if (PathHelper.IsMatch(fullName, Excludes, Flags))
+                if (PathHelper.IsMatch(fullName, Excludes, flags))
                     continue;
 
                 if (ShouldRecursePredicate == null || ShouldRecursePredicate(entry))
-                    if (PathHelper.IsPartialMatch(fullName, Patterns, Flags))
+                    if (PathHelper.IsPartialMatch(fullName, Patterns, flags))
                         queue.Enqueue((entry, fullName.ToString()));
 
                 if (ShouldIncludePredicate == null || ShouldIncludePredicate(entry))
-                    if (PathHelper.IsMatch(fullName, Patterns, Flags))
+                    if (PathHelper.IsMatch(fullName, Patterns, flags))
                         yield return ResultSelector(entry);
             }
         }
diff --git a/Ramstack.Globbing/Traversal/Files.Utilities.cs b/Ramstack.Globbing/Traversal/Files.Utilities.cs
index 58f29fe..f2da1f5 100644
--- a/Ramstack.Globbing/Traversal/Files.Utilities.cs
+++ b/Ramstack.Globbing/Traversal/Files.Utilities.cs
@@ -21,7 +21,9 @@ partial class Files
     /// <param name="entry">A file system entry reference.</param>
     /// <param name="patterns">An array of glob patterns to match against the names of files.</param>
     /// <param name="excludes">Optional array of glob patterns to exclude files.</param>
-    /// <param name="flags">The matching options to use.</param>
+    /// <param name="flags">The matching options to use.
+    /// This parameter must be explicitly set to either <see cref="MatchFlags.Windows"/> or <see cref="MatchFlags.Unix"/>.
+    /// <see cref="MatchFlags.Auto"/> is not allowed and will result in an assertion failure.</param>
     /// <param name="target">The search target.</param>
     /// <returns>
     /// <see langword="true" /> if the specified file system entry should be included in the results;
@@ -29,6 +31,8 @@ partial class Files
     /// </returns>
     internal static bool ShouldInclude(ref FileSystemEntry entry, string[] patterns, string[] excludes, MatchFlags flags, SearchTarget target)
     {
+        Debug.Assert(flags != MatchFlags.Auto);
+
         char[]? rented = null;
 
         var current = entry.IsDirectory
@@ -60,13 +64,17 @@ internal static bool ShouldInclude(ref FileSystemEntry entry, string[] patterns,
     /// <param name="entry">A file system entry reference.</param>
     /// <param name="patterns">An array of glob patterns to match against the names of files.</param>
     /// <param name="excludes">Optional array of glob patterns to exclude files.</param>
-    /// <param name="flags">The matching options to use. Default is <see cref="MatchFlags.Auto"/>.</param>
+    /// <param name="flags">The matching options to use.
+    /// This parameter must be explicitly set to either <see cref="MatchFlags.Windows"/> or <see cref="MatchFlags.Unix"/>.
+    /// <see cref="MatchFlags.Auto"/> is not allowed and will result in an assertion failure.</param>
     /// <returns>
     /// <see langword="true" /> if the specified directory entry should be recursed into;
     /// otherwise, <see langword="false" />.
     /// </returns>
     internal static bool ShouldRecurse(ref FileSystemEntry entry, string[] patterns, string[] excludes, MatchFlags flags)
     {
+        Debug.Assert(flags != MatchFlags.Auto);
+
         char[]? rented = null;
 
         var length = GetRelativePathLength(ref entry);
@@ -88,15 +96,16 @@ internal static bool ShouldRecurse(ref FileSystemEntry entry, string[] patterns,
     }
 
     /// <summary>
-    /// Adjusts the provided match flags based on the current operating system's directory separator character.
+    /// Resolves the provided match flags by converting <see cref="MatchFlags.Auto"/>
+    /// to a concrete value based on the current operating system's directory separator convention.
     /// </summary>
     /// <param name="flags">The initial match flags to resolve.</param>
     /// <returns>
-    /// The adjusted match flags. If the initial flags are <see cref="MatchFlags.Auto"/>, the method returns
-    /// <see cref="MatchFlags.Windows"/> for Windows systems and <see cref="MatchFlags.Unix"/> for Unix-like systems;
-    /// otherwise, it returns the provided flags.
+    /// The resolved match flags. If the input is <see cref="MatchFlags.Auto"/>, returns
+    /// <see cref="MatchFlags.Windows"/> on Windows systems and <see cref="MatchFlags.Unix"/>
+    /// on Unix-like systems. Otherwise, returns the original flags unchanged.
     /// </returns>
-    internal static MatchFlags AdjustMatchFlags(MatchFlags flags)
+    internal static MatchFlags ResolveMatchFlags(MatchFlags flags)
     {
         if (flags == MatchFlags.Auto)
             return Path.DirectorySeparatorChar == '\\'
@@ -144,6 +153,8 @@ private static int GetRelativePathLength(ref FileSystemEntry entry)
 
     private static void UpdatePathSeparators(scoped Span<char> path, MatchFlags flags)
     {
+        Debug.Assert(flags != MatchFlags.Auto);
+
         // To enable escaping in Windows systems, we convert backslashes (\) to forward slashes (/).
         // This is safe because in Windows, backslashes are only used as path separators.
         // Otherwise, the backslash (\) in the path will be treated as an escape character,
diff --git a/Ramstack.Globbing/Traversal/Files.cs b/Ramstack.Globbing/Traversal/Files.cs
index f04def3..21a643e 100644
--- a/Ramstack.Globbing/Traversal/Files.cs
+++ b/Ramstack.Globbing/Traversal/Files.cs
@@ -753,7 +753,7 @@ public static IEnumerable<string> EnumerateFileSystemEntries(string path, string
 
     private static IEnumerable<string> EnumerateEntries(string path, string[] patterns, string[] excludes, MatchFlags flags, SearchTarget target, EnumerationOptions options)
     {
-        flags = AdjustMatchFlags(flags);
+        flags = ResolveMatchFlags(flags);
 
         return new FileSystemEnumerable<string>(Path.GetFullPath(path), (ref entry) => entry.ToFullPath(), options)
         {