diff --git a/tests/NetVips.Tests/ColourTests.cs b/tests/NetVips.Tests/ColourTests.cs
index b9aa461..97c7592 100644
--- a/tests/NetVips.Tests/ColourTests.cs
+++ b/tests/NetVips.Tests/ColourTests.cs
@@ -1,4 +1,3 @@
-using System;
 using System.Linq;
 using Xunit;
 using Xunit.Abstractions;
diff --git a/tests/NetVips.Tests/ConnectionTests.cs b/tests/NetVips.Tests/ConnectionTests.cs
index f706677..33c7469 100644
--- a/tests/NetVips.Tests/ConnectionTests.cs
+++ b/tests/NetVips.Tests/ConnectionTests.cs
@@ -1,6 +1,5 @@
 using System;
 using System.IO;
-using System.Text;
 using Xunit;
 using Xunit.Abstractions;
 
diff --git a/tests/NetVips.Tests/CreateTests.cs b/tests/NetVips.Tests/CreateTests.cs
index 948cf57..435bbfe 100644
--- a/tests/NetVips.Tests/CreateTests.cs
+++ b/tests/NetVips.Tests/CreateTests.cs
@@ -1,4 +1,3 @@
-using System;
 using Xunit;
 using Xunit.Abstractions;