diff --git a/build/automation.py.in b/build/automation.py.in
index cc95f7b18ce9..26d7a518e650 100644
--- a/build/automation.py.in
+++ b/build/automation.py.in
@@ -159,6 +159,7 @@ class Automation(object):
   def __init__(self):
     self.log = _log
     self.lastTestSeen = "automation.py"
+    self.haveDumpedScreen = False
 
   def setServerInfo(self, 
                     webServer = _DEFAULT_WEB_SERVER, 
@@ -655,8 +656,34 @@ user_pref("camino.use_system_proxy_settings", false); // Camino-only, harmless t
     def killPid(self, pid):
       os.kill(pid, signal.SIGKILL)
 
+  if UNIXISH:
+    def dumpScreen(self, utilityPath):
+      self.haveDumpedScreen = True;
+
+      screentopng = os.path.join(utilityPath, "screentopng")
+      try:
+        dumper = self.Process([screentopng], bufsize=-1,
+                              stdout=subprocess.PIPE, close_fds=True)
+      except OSError, err:
+        self.log.info("Failed to start %s for screenshot: %s",
+                      screentopng, err.strerror)
+        return
+
+      image = dumper.stdout.read()
+      status = dumper.wait()
+      if status != 0:
+        self.log.info("screentopng exited with code %d", status)
+        return
+
+      import base64
+      encoded = base64.b64encode(image)
+      self.log.info("SCREENSHOT: data:image/png;base64,%s", encoded)
+
   def killAndGetStack(self, proc, utilityPath, debuggerInfo):
     """Kill the process, preferrably in a way that gets us a stack trace."""
+    if self.UNIXISH and not debuggerInfo and not self.haveDumpedScreen:
+      self.dumpScreen(utilityPath)
+
     if self.CRASHREPORTER and not debuggerInfo:
       if self.UNIXISH:
         # ABRT will get picked up by Breakpad's signal handler
@@ -710,6 +737,9 @@ user_pref("camino.use_system_proxy_settings", false); // Camino-only, harmless t
         if stackFixerFunction:
           line = stackFixerFunction(line)
         self.log.info(line.rstrip())
+        if self.UNIXISH and not debuggerInfo and not self.haveDumpedScreen and "TEST-UNEXPECTED-FAIL" in line and "Test timed out." in line:
+          self.dumpScreen(utilityPath)
+
         (line, didTimeout) = self.readWithTimeout(logsource, timeout)
         if not hitMaxTime and maxTime and datetime.now() - startTime > timedelta(seconds = maxTime):
           # Kill the application, but continue reading from stack fixer so as not to deadlock on stackFixerProcess.wait().
diff --git a/testing/mochitest/Makefile.in b/testing/mochitest/Makefile.in
index 7cf20d7b8674..0a20c80c7d99 100644
--- a/testing/mochitest/Makefile.in
+++ b/testing/mochitest/Makefile.in
@@ -145,6 +145,10 @@ ifeq ($(OS_ARCH),Linux)
 TEST_HARNESS_BINS += fix-linux-stack.pl
 endif
 
+ifeq (gtk2_1,$(MOZ_WIDGET_TOOLKIT)_$(MOZ_X11))
+TEST_HARNESS_BINS += screentopng
+endif
+
 # Components / typelibs that don't get packaged with
 # the build, but that we need for the test harness.
 TEST_HARNESS_COMPONENTS := \