diff --git a/mps/code/event.c b/mps/code/event.c
index 1bdbafb34f6..96e78b24061 100644
--- a/mps/code/event.c
+++ b/mps/code/event.c
@@ -404,6 +404,13 @@ void EventDump(mps_lib_FILE *stream)
 
   AVER(stream != NULL);
 
+  /* This can happen if there's a backtrace very early in the life of
+     the MPS, and will cause an access violation if we continue. */
+  if (!eventInited) {
+    WriteF(stream, "No events\n", NULL);
+    return;
+  }
+
   for (kind = 0; kind < EventKindLIMIT; ++kind) {
     for (event = (Event)EventLast[kind];
          event < (Event)(EventBuffer[kind] + EventBufferSIZE);