diff --git a/src/org/labkey/test/Runner.java b/src/org/labkey/test/Runner.java
index fa66122575..06290f096d 100644
--- a/src/org/labkey/test/Runner.java
+++ b/src/org/labkey/test/Runner.java
@@ -220,6 +220,7 @@ private static void saveTestDuration(Test currentWebTest, long durationMs)
     @Override
     public synchronized void runTest(final Test test, final TestResult testResult)
     {
+        System.setProperty("java.awt.headless", "false"); // Prevent `java.awt.HeadlessException` on Windows on TeamCity
         long startTimeMs = System.currentTimeMillis();
         if (_cleanOnly)
         {