diff --git a/fast-import.c b/fast-import.c
index 9363cc7829..1343865278 100644
--- a/fast-import.c
+++ b/fast-import.c
@@ -421,7 +421,7 @@ static void write_crash_report(const char *err)
 	fprintf(rpt, "fast-import crash report:\n");
 	fprintf(rpt, "    fast-import process: %"PRIuMAX"\n", (uintmax_t) getpid());
 	fprintf(rpt, "    parent process     : %"PRIuMAX"\n", (uintmax_t) getppid());
-	fprintf(rpt, "    at %s\n", show_date(time(NULL), 0, DATE_MODE(LOCAL)));
+	fprintf(rpt, "    at %s\n", show_date(time(NULL), 0, DATE_MODE(ISO8601)));
 	fputc('\n', rpt);
 
 	fputs("fatal: ", rpt);