diff --git a/src/Spectre.Console/Internal/Text/Markup/MarkupTokenizer.cs b/src/Spectre.Console/Internal/Text/Markup/MarkupTokenizer.cs
index df62a94..6ed39df 100644
--- a/src/Spectre.Console/Internal/Text/Markup/MarkupTokenizer.cs
+++ b/src/Spectre.Console/Internal/Text/Markup/MarkupTokenizer.cs
@@ -66,13 +66,39 @@ internal sealed class MarkupTokenizer : IDisposable
             var builder = new StringBuilder();
             while (!_reader.Eof)
             {
-                current = _reader.Peek();
-                if (current == ']')
+                current = _reader.Read();
+                var next = '\0';
+                if (!_reader.Eof)
                 {
-                    break;
+                    next = _reader.Peek();
                 }
 
-                builder.Append(_reader.Read());
+                if (current == ']')
+                {
+                    if (next != ']')
+                    {
+                        break;
+                    }
+
+                    _reader.Read();
+                }
+
+                builder.Append(current);
+
+                if (current != '[')
+                {
+                    continue;
+                }
+
+                if (next == '[')
+                {
+                    _reader.Read();
+                }
+                else
+                {
+                    throw new InvalidOperationException(
+                        $"Encountered malformed markup tag at position {_reader.Position - 1}.");
+                }
             }
 
             if (_reader.Eof)
@@ -80,7 +106,6 @@ internal sealed class MarkupTokenizer : IDisposable
                 throw new InvalidOperationException($"Encountered malformed markup tag at position {_reader.Position}.");
             }
 
-            _reader.Read();
             Current = new MarkupToken(MarkupTokenKind.Open, builder.ToString(), position);
             return true;
         }
diff --git a/test/Spectre.Console.Tests/Unit/AnsiConsoleTests.Markup.cs b/test/Spectre.Console.Tests/Unit/AnsiConsoleTests.Markup.cs
index 325ed53..58d0a90 100644
--- a/test/Spectre.Console.Tests/Unit/AnsiConsoleTests.Markup.cs
+++ b/test/Spectre.Console.Tests/Unit/AnsiConsoleTests.Markup.cs
@@ -100,6 +100,7 @@ public partial class AnsiConsoleTests
         [InlineData("[yellow]Hello[/", "Encountered malformed markup tag at position 15.")]
         [InlineData("[yellow]Hello[/foo", "Encountered malformed markup tag at position 15.")]
         [InlineData("[yellow Hello", "Encountered malformed markup tag at position 13.")]
+        [InlineData("[yellow[green]]Hello", "Encountered malformed markup tag at position 7.")]
         public void Should_Throw_If_Encounters_Malformed_Tag(string markup, string expected)
         {
             // Given