diff --git a/HtmlMinifier.Tests/FileExtensionTests.cs b/HtmlMinifier.Tests/FileExtensionTests.cs
new file mode 100644
index 0000000..3652373
--- /dev/null
+++ b/HtmlMinifier.Tests/FileExtensionTests.cs
@@ -0,0 +1,19 @@
+using NUnit.Framework;
+using System.Collections.Generic;
+
+namespace HtmlMinifier.Tests
+{
+    [TestFixture]
+    public class FileExtensionTests
+    {
+        [Test]
+        public void GithubIssue25__ShouldReturnCorrectly()
+        {                        
+            Assert.That("test.html".IsHtmlFile(), Is.True);
+            Assert.That("codes.js.aspx".IsHtmlFile(), Is.True);
+
+            Assert.That("codes.aspx.js".IsHtmlFile(), Is.False);
+            Assert.That("aspx.codes.js".IsHtmlFile(), Is.False);
+        }
+    }
+}
diff --git a/HtmlMinifier.Tests/HtmlMinifier.Tests.csproj b/HtmlMinifier.Tests/HtmlMinifier.Tests.csproj
index f6c5248..c857a64 100644
--- a/HtmlMinifier.Tests/HtmlMinifier.Tests.csproj
+++ b/HtmlMinifier.Tests/HtmlMinifier.Tests.csproj
@@ -44,6 +44,7 @@
   <ItemGroup>
     <Compile Include="ArgumentsTests.cs" />
     <Compile Include="DataHelpers.cs" />
+    <Compile Include="FileExtensionTests.cs" />
     <Compile Include="MinificationTests.cs" />
     <Compile Include="Properties\AssemblyInfo.cs" />
   </ItemGroup>