diff --git a/tests/Nfdi4Plants.Fornax.Tests/Main.fs b/tests/Nfdi4Plants.Fornax.Tests/Main.fs
index 3358307..d367b38 100644
--- a/tests/Nfdi4Plants.Fornax.Tests/Main.fs
+++ b/tests/Nfdi4Plants.Fornax.Tests/Main.fs
@@ -7,6 +7,7 @@ open Tests.MarkdigExtensions
 let allTests = testList "" [
     Nfdi4PlantsSidebarHeader.tests
     Nfdi4PlantsHeader.tests
+    Nfdi4PlantsCodeBlock.tests
 ]
 
 [<EntryPoint>]
diff --git a/tests/Nfdi4Plants.Fornax.Tests/Nfdi4Plants.Fornax.Tests.fsproj b/tests/Nfdi4Plants.Fornax.Tests/Nfdi4Plants.Fornax.Tests.fsproj
index da00cfc..7aad4e5 100644
--- a/tests/Nfdi4Plants.Fornax.Tests/Nfdi4Plants.Fornax.Tests.fsproj
+++ b/tests/Nfdi4Plants.Fornax.Tests/Nfdi4Plants.Fornax.Tests.fsproj
@@ -1,24 +1,21 @@
-<Project Sdk="Microsoft.NET.Sdk">
-
+<Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
     <OutputType>Exe</OutputType>
     <TargetFramework>net5.0</TargetFramework>
     <GenerateProgramFile>false</GenerateProgramFile>
   </PropertyGroup>
-
   <ItemGroup>
+    <Compile Include="nfdi-code.tests.fs" />
     <Compile Include="nfdi-header.tests.fs" />
     <Compile Include="nfdi-sidebar-element-header.tests.fs" />
     <Compile Include="main.fs" />
   </ItemGroup>
-
   <ItemGroup>
     <PackageReference Include="Expecto" Version="9.*" />
     <PackageReference Include="YoloDev.Expecto.TestSdk" Version="0.*" />
     <PackageReference Include="Microsoft.NET.Test.Sdk" Version="16.*" />
   </ItemGroup>
-
   <ItemGroup>
-	<ProjectReference Include="..\..\src\Nfdi4Plants.Fornax\Nfdi4Plants.Fornax.fsproj" />
+    <ProjectReference Include="..\..\src\Nfdi4Plants.Fornax\Nfdi4Plants.Fornax.fsproj" />
   </ItemGroup>
-</Project>
+</Project>
\ No newline at end of file
diff --git a/tests/Nfdi4Plants.Fornax.Tests/nfdi-code.tests.fs b/tests/Nfdi4Plants.Fornax.Tests/nfdi-code.tests.fs
new file mode 100644
index 0000000..9548b90
--- /dev/null
+++ b/tests/Nfdi4Plants.Fornax.Tests/nfdi-code.tests.fs
@@ -0,0 +1,44 @@
+module Tests.MarkdigExtensions.Nfdi4PlantsCodeBlock
+
+open Expecto
+open Fornax.Nfdi4Plants
+open Fornax.Nfdi4Plants.MarkdigExtensions.NfdiCode
+open Markdig
+
+let pipeline = 
+    let builder = new MarkdownPipelineBuilder()
+    builder
+        .UseAdvancedExtensions()
+        .UseEmojiAndSmiley()
+        .UseNFDICodeBlock()
+        .Build()
+
+[<Tests>]
+let tests = 
+    testList "UseNFDICodeBlock" [
+        test "basic case" {
+            let markdown = """Here is some inline `code`!"""
+            let result = Markdown.ToHtml(markdown, pipeline)
+            Expect.equal result $"""<p>Here is some inline <code>code</code>!</p>{'\010'}""" ""
+        }
+        test "Fenced code block, no language" {
+            let markdown = """Test line
+```
+let someCode = 42
+```
+"""
+            let result = Markdown.ToHtml(markdown, pipeline).Trim()
+            let expected = $"""<p>Test line</p>{'\010'}<nfdi-code>let someCode = 42</nfdi-code>""".Trim()
+            Expect.equal result expected ""
+        }
+        test "Fenced code block" {
+            let markdown = """Test line
+```fsharp
+let someCode = 42
+```
+"""
+            let result = Markdown.ToHtml(markdown, pipeline)
+            let expected = $"""<p>Test line</p>{'\010'}<nfdi-code class="language-fsharp">let someCode = 42</nfdi-code>"""
+            Expect.equal result expected ""
+        }
+    ]
\ No newline at end of file