diff --git a/toolkit/crashreporter/test/CrashTestUtils.jsm b/toolkit/crashreporter/test/CrashTestUtils.jsm
index 39d6b9052c8..18f9d42d527 100644
--- a/toolkit/crashreporter/test/CrashTestUtils.jsm
+++ b/toolkit/crashreporter/test/CrashTestUtils.jsm
@@ -42,6 +42,13 @@ CrashTestUtils.lockDir = lib.declare("LockDir",
                                      ctypes.voidptr_t);  // nsISupports*
 
 
+try {
+  CrashTestUtils.TryOverrideExceptionHandler = lib.declare("TryOverrideExceptionHandler",
+                                                           ctypes.default_abi,
+                                                           ctypes.void_t);
+}
+catch(ex) {}
+
 CrashTestUtils.dumpHasStream = lib.declare("DumpHasStream",
                                            ctypes.default_abi,
                                            ctypes.bool,
diff --git a/toolkit/crashreporter/test/nsTestCrasher.cpp b/toolkit/crashreporter/test/nsTestCrasher.cpp
index 4e9147c88a9..a824bd6d723 100644
--- a/toolkit/crashreporter/test/nsTestCrasher.cpp
+++ b/toolkit/crashreporter/test/nsTestCrasher.cpp
@@ -104,3 +104,17 @@ uint64_t SaveAppMemory()
 
   return (int64_t)testData;
 }
+
+#ifdef XP_WIN32
+static LONG WINAPI HandleException(EXCEPTION_POINTERS* exinfo)
+{
+  TerminateProcess(GetCurrentProcess(), 0);
+  return 0;
+}
+
+extern "C" NS_EXPORT
+void TryOverrideExceptionHandler()
+{
+  SetUnhandledExceptionFilter(HandleException);
+}
+#endif
diff --git a/toolkit/crashreporter/test/unit/test_override_exception_handler.js b/toolkit/crashreporter/test/unit/test_override_exception_handler.js
new file mode 100644
index 00000000000..7e7787d80e7
--- /dev/null
+++ b/toolkit/crashreporter/test/unit/test_override_exception_handler.js
@@ -0,0 +1,12 @@
+function run_test()
+{
+  // Ensure that attempting to override the exception handler doesn't cause
+  // us to lose our exception handler.
+  do_crash(
+    function() {
+        CrashTestUtils.TryOverrideExceptionHandler();
+    },
+    function(mdump, extra) {
+    },
+    true);
+}
diff --git a/toolkit/crashreporter/test/unit/xpcshell.ini b/toolkit/crashreporter/test/unit/xpcshell.ini
index fce8bbc9fd6..7c147187d46 100644
--- a/toolkit/crashreporter/test/unit/xpcshell.ini
+++ b/toolkit/crashreporter/test/unit/xpcshell.ini
@@ -11,6 +11,8 @@ skip-if = os == 'win' && debug
 [test_crashreporter.js]
 [test_crashreporter_crash.js]
 [test_crashreporter_crash_profile_lock.js]
+[test_override_exception_handler.js]
+run-if = os == 'win'
 
 [test_crashreporter_appmem.js]
 run-if = os == 'win' || os == 'linux'