diff --git a/src/tests/TestSSLLocks/TestSSLLocks.cpp b/src/tests/TestSSLLocks/TestSSLLocks.cpp
new file mode 100644
index 00000000000..9963c43506a
--- /dev/null
+++ b/src/tests/TestSSLLocks/TestSSLLocks.cpp
@@ -0,0 +1,106 @@
+// Copyright 2005-2017 The Mumble Developers. All rights reserved.
+// Use of this source code is governed by a BSD-style license
+// that can be found in the LICENSE file at the root of the
+// Mumble source tree or at <https://www.mumble.info/LICENSE>.
+
+#include <QtCore>
+#include <QtTest>
+
+#include "SSL.h"
+#include "QAtomicIntCompat.h"
+
+#include <openssl/rand.h>
+
+/// SSLRacer is a thread that runs operations on OpenSSL's
+/// RAND infrastructure, in an attempt to crash/segfault
+/// the test process.
+///
+/// The thread can either query OpenSSL for random bytes, or
+/// seed the RAND system. This is controlled by the |seed|
+/// parameter to the constructor.
+class SSLRacer : public QThread {
+public:
+	bool m_seed;
+	QAtomicInt *m_running;
+
+	SSLRacer(QAtomicInt *running, bool seed)
+		: m_seed(seed)
+		, m_running(running) {
+	}
+
+	void run() {
+		unsigned char buf[64];
+		while (QAtomicIntLoad(*m_running) == 1) {
+			for (int i = 0; i < 1024; i++) {
+				if (m_seed) {
+					RAND_seed(buf, sizeof(buf));
+				} else {
+					RAND_bytes(buf, sizeof(buf));
+				}
+			}
+		}
+	}
+};
+
+class TestSSLLocks : public QObject {
+		Q_OBJECT
+	private slots:
+		void initTestCase();
+		void cleanupTestCase();
+		void stress();
+};
+
+void TestSSLLocks::initTestCase() {
+	// For OpenSSL < 1.1, if you comment out this line,
+	// you'll be running OpenSSL without locking callbacks
+	// enabled. That'll make this test fail by crashing/segfaulting.
+	MumbleSSL::initialize();
+}
+
+void TestSSLLocks::cleanupTestCase() {
+	MumbleSSL::destroy();
+}
+
+/// Stress test that our locking callbacks for OpenSSL are set up and
+/// working correctly.
+///
+/// We do this by spawning a bunch of SSLStresser threads. Some of the
+/// threads will try to read random bytes in a tight loop. Other threads
+/// will, at the same time, try to add/seed random bytes to the OpenSSL
+/// RAND system.
+///
+/// The idea is that without proper locking, the data races we're causing
+/// should quite quickly cause the process to crash.
+void TestSSLLocks::stress() {
+	std::vector<SSLRacer *> racers;
+	QAtomicInt running(1);
+
+	// Spawn 24 threads in total. 12 readers, and 12 writers.
+	// Don't be too careful about cleaning up the threads. We'll either
+	// pass or crash, so the threads will be cleaned up either way.
+	int nthreads = 24;
+	for (int i = 0; i < nthreads; i++) {
+		bool seeder = i % 2;
+		SSLRacer *racer = new SSLRacer(&running, seeder);
+		racers.push_back(racer);
+		racer->start();
+	}
+
+	// Wait 2 seconds for a crash/segfault.
+	// If we don't crash within 2 seconds, we expect
+	// that our locking implementation works.
+	QTest::qSleep(2000);
+
+	// Signal to the racers that they should stop.
+	running.fetchAndStoreOrdered(0);
+
+	// Wait for all racers to complete.
+	for (size_t i = 0; i < racers.size(); i++) {
+		SSLRacer *racer = racers.at(i);
+		racer->wait();
+		delete racer;
+	}
+}
+
+QTEST_MAIN(TestSSLLocks)
+#include "TestSSLLocks.moc"
diff --git a/src/tests/TestSSLLocks/TestSSLLocks.pro b/src/tests/TestSSLLocks/TestSSLLocks.pro
new file mode 100644
index 00000000000..443c1b25703
--- /dev/null
+++ b/src/tests/TestSSLLocks/TestSSLLocks.pro
@@ -0,0 +1,12 @@
+# Copyright 2005-2017 The Mumble Developers. All rights reserved.
+# Use of this source code is governed by a BSD-style license
+# that can be found in the LICENSE file at the root of the
+# Mumble source tree or at <https://www.mumble.info/LICENSE>.
+
+include(../test.pri)
+
+QT += network
+
+TARGET = TestSSLLocks
+SOURCES = SSL.cpp SSLLocks.cpp TestSSLLocks.cpp
+HEADERS = SSL.h SSLLocks.h
diff --git a/src/tests/tests.pro b/src/tests/tests.pro
index 2b608453baf..5ba7cf603a4 100644
--- a/src/tests/tests.pro
+++ b/src/tests/tests.pro
@@ -16,4 +16,5 @@ SUBDIRS += \
 	TestUnresolvedServerAddress \
 	TestServerAddress \
 	TestServerResolver \
-	TestSelfSignedCertificate
+	TestSelfSignedCertificate \
+	TestSSLLocks