diff --git a/bramble-api/src/test/java/org/briarproject/bramble/test/BrambleTestCase.java b/bramble-api/src/test/java/org/briarproject/bramble/test/BrambleTestCase.java
index 9fae78043..9ac8a7a40 100644
--- a/bramble-api/src/test/java/org/briarproject/bramble/test/BrambleTestCase.java
+++ b/bramble-api/src/test/java/org/briarproject/bramble/test/BrambleTestCase.java
@@ -1,17 +1,42 @@
 package org.briarproject.bramble.test;
 
-import java.lang.Thread.UncaughtExceptionHandler;
+import org.junit.After;
+import org.junit.Before;
 
-import static org.junit.Assert.fail;
+import java.lang.Thread.UncaughtExceptionHandler;
+import java.util.logging.Level;
+import java.util.logging.Logger;
+
+import javax.annotation.Nullable;
+
+import static java.util.logging.Logger.getLogger;
 
 public abstract class BrambleTestCase {
 
+	private static final Logger LOG =
+			getLogger(BrambleTestCase.class.getName());
+
+	@Nullable
+	protected volatile Throwable exceptionInBackgroundThread = null;
+
 	public BrambleTestCase() {
 		// Ensure exceptions thrown on worker threads cause tests to fail
 		UncaughtExceptionHandler fail = (thread, throwable) -> {
-			throwable.printStackTrace();
-			fail();
+			LOG.log(Level.WARNING, "Caught unhandled exception", throwable);
+			exceptionInBackgroundThread = throwable;
 		};
 		Thread.setDefaultUncaughtExceptionHandler(fail);
 	}
+
+	@Before
+	public void beforeBrambleTestCase() {
+		exceptionInBackgroundThread = null;
+	}
+
+	@After
+	public void afterBrambleTestCase() {
+		Throwable thrown = exceptionInBackgroundThread;
+		LOG.warning("background thread has thrown an exception unexpectedly");
+		if (thrown != null) throw new AssertionError(thrown);
+	}
 }
diff --git a/bramble-api/src/test/java/org/briarproject/bramble/test/ThreadExceptionTest.java b/bramble-api/src/test/java/org/briarproject/bramble/test/ThreadExceptionTest.java
new file mode 100644
index 000000000..14a5d21bb
--- /dev/null
+++ b/bramble-api/src/test/java/org/briarproject/bramble/test/ThreadExceptionTest.java
@@ -0,0 +1,36 @@
+package org.briarproject.bramble.test;
+
+import org.junit.Test;
+
+import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.fail;
+
+public class ThreadExceptionTest extends BrambleTestCase {
+
+	@Test(expected = AssertionError.class)
+	public void testAssertionErrorMakesTestCaseFail() {
+		// This is what BrambleTestCase does, too:
+		fail();
+	}
+
+	@Test
+	public void testExceptionInThreadMakesTestCaseFail() {
+		Thread t = new Thread(() -> {
+			System.out.println("thread before exception");
+			throw new RuntimeException("boom");
+		});
+
+		t.start();
+		try {
+			t.join();
+			System.out.println("joined thread");
+		} catch (InterruptedException e) {
+			System.out.println("interrupted while joining thread");
+			fail();
+		}
+
+		assertNotNull(exceptionInBackgroundThread);
+		exceptionInBackgroundThread = null;
+	}
+
+}
diff --git a/briar-core/src/test/java/org/briarproject/briar/introduction/IntroductionIntegrationTest.java b/briar-core/src/test/java/org/briarproject/briar/introduction/IntroductionIntegrationTest.java
index 952576c98..29131fe8b 100644
--- a/briar-core/src/test/java/org/briarproject/briar/introduction/IntroductionIntegrationTest.java
+++ b/briar-core/src/test/java/org/briarproject/briar/introduction/IntroductionIntegrationTest.java
@@ -986,6 +986,10 @@ public class IntroductionIntegrationTest
 	@Test
 	public void testIntroduceesRemovedCleanup() throws Exception {
 		addListeners(true, true);
+		// The second introducee shouldn't respond to the introduction
+		// otherwise there would be a race between the response to the REQUEST
+		// and the delivery of the ABORT
+		listener2.answerRequests = false;
 
 		// make introduction
 		introductionManager0