diff --git a/tycho-its/src/test/java/org/eclipse/tycho/test/p2Repository/P2RepositoryPropertiesTest.java b/tycho-its/src/test/java/org/eclipse/tycho/test/p2Repository/P2RepositoryPropertiesTest.java
index 0a4714c5d8..56c41f2147 100644
--- a/tycho-its/src/test/java/org/eclipse/tycho/test/p2Repository/P2RepositoryPropertiesTest.java
+++ b/tycho-its/src/test/java/org/eclipse/tycho/test/p2Repository/P2RepositoryPropertiesTest.java
@@ -78,4 +78,10 @@ public void testPropertyPropagation() throws Exception {
 		assertTrue(properties.containsKey(TychoConstants.PROP_PGP_SIGNATURES)
 				&& !properties.get(TychoConstants.PROP_PGP_SIGNATURES).isBlank());
 	}
+
+	@Override
+	protected boolean isDisableMirrors() {
+		// we want to test mirror properties...
+		return false;
+	}
 }
diff --git a/tycho-testing-harness/src/main/java/org/eclipse/tycho/test/AbstractTychoIntegrationTest.java b/tycho-testing-harness/src/main/java/org/eclipse/tycho/test/AbstractTychoIntegrationTest.java
index e0505f8331..5254ea12d8 100644
--- a/tycho-testing-harness/src/main/java/org/eclipse/tycho/test/AbstractTychoIntegrationTest.java
+++ b/tycho-testing-harness/src/main/java/org/eclipse/tycho/test/AbstractTychoIntegrationTest.java
@@ -90,6 +90,9 @@ protected Verifier getVerifier(String test, boolean setTargetPlatform, File user
 
         Verifier verifier = new Verifier(testDir.getAbsolutePath());
         verifier.setForkJvm(isForked());
+        if (isDisableMirrors()) {
+            verifier.setSystemProperty("tycho.disableP2Mirrors", "true");
+        }
         String debug = System.getProperty("tycho.mvnDebug");
         if (debug != null) {
             System.out.println("Preparing to execute Maven in debug mode");
@@ -146,6 +149,14 @@ protected Verifier getVerifier(String test, boolean setTargetPlatform, File user
 
     }
 
+    /**
+     * can be overridden by subclass to explicitly enable mirrors, by default they are disabled.
+     * 
+     */
+    protected boolean isDisableMirrors() {
+        return true;
+    }
+
     protected boolean isForked() {
         return true;
     }