diff --git a/picocli-codegen/src/test/java/picocli/codegen/docgen/manpage/ManPageGeneratorTest.java b/picocli-codegen/src/test/java/picocli/codegen/docgen/manpage/ManPageGeneratorTest.java
index ea6d390b..64012774 100644
--- a/picocli-codegen/src/test/java/picocli/codegen/docgen/manpage/ManPageGeneratorTest.java
+++ b/picocli-codegen/src/test/java/picocli/codegen/docgen/manpage/ManPageGeneratorTest.java
@@ -1,6 +1,10 @@
 package picocli.codegen.docgen.manpage;
 
+import org.junit.Rule;
 import org.junit.Test;
+import org.junit.contrib.java.lang.system.ProvideSystemProperty;
+import org.junit.contrib.java.lang.system.RestoreSystemProperties;
+import org.junit.rules.TestRule;
 import picocli.CommandLine;
 import picocli.CommandLine.ArgGroup;
 import picocli.CommandLine.Command;
@@ -24,6 +28,11 @@ import java.util.concurrent.Callable;
 import static org.junit.Assert.*;
 
 public class ManPageGeneratorTest {
+    @Rule
+    public final TestRule restoreSystemProperties = new RestoreSystemProperties();
+
+    @Rule
+    public final ProvideSystemProperty ansiOFF = new ProvideSystemProperty("picocli.ansi", "false");
 
     @Test
     public void generateManPage() throws IOException {