diff --git a/src/System.CommandLine.StaticCompletions/CompletionsCommand.cs b/src/System.CommandLine.StaticCompletions/CompletionsCommand.cs
index d6ee05b6d353..7e778d4e4fcb 100644
--- a/src/System.CommandLine.StaticCompletions/CompletionsCommand.cs
+++ b/src/System.CommandLine.StaticCompletions/CompletionsCommand.cs
@@ -67,8 +67,8 @@ static IShellProvider LookupShellFromEnvironment(Dictionary<string, IShellProvid
             {
                 throw new InvalidOperationException(Strings.ShellDiscovery_ShellEnvironmentNotSet);
             }
-            var shellName = Path.GetFileName(shellPath);
-            if (shellMap.TryGetValue(shellPath, out var shellProvider))
+            var shellName = Path.GetFileName(shellPath).ToLower();
+            if (shellMap.TryGetValue(shellName, out var shellProvider))
             {
                 return shellProvider;
             }
diff --git a/test/dotnet.Tests/CompletionTests/ShellDiscoveryTests.cs b/test/dotnet.Tests/CompletionTests/ShellDiscoveryTests.cs
new file mode 100644
index 000000000000..08099acc8cea
--- /dev/null
+++ b/test/dotnet.Tests/CompletionTests/ShellDiscoveryTests.cs
@@ -0,0 +1,24 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+#nullable disable
+
+
+using System.CommandLine.StaticCompletions.Shells;
+using Microsoft.DotNet.Cli.Commands.BuildServer.Shutdown;
+using Microsoft.Extensions.Options;
+using Xunit;
+using Parser = Microsoft.DotNet.Cli.Parser;
+
+namespace System.CommandLine.StaticCompletions.Tests;
+
+public class ShellDiscoveryTests
+{
+    [Fact]
+    public void StaticCompletionsCanParseWithoutAShell()
+    {
+        ParseResult result = Parser.Parse(["dotnet", "completions", "script"]);
+        result.Errors.Should().BeEmpty();
+        result.GetValue<IShellProvider>("@CompletionsCommand_ShellArgument_Description").Should().NotBeNull();
+    }
+}