diff --git a/queries.c b/queries.c
index 72d6962..5856f36 100644
--- a/queries.c
+++ b/queries.c
@@ -321,8 +321,8 @@ void do_insert_header (void) {
     struct utsname st;
     uname (&st);
     out_string (st.machine);
-    static char buf[1000000];
-    sprintf (buf, "%s %s %s", st.sysname, st.release, st.version);
+    static char buf[65536];
+    sprintf (buf, "%999s %999s %999s", st.sysname, st.release, st.version);
     out_string (buf);
     out_string (TG_VERSION " (build " TG_BUILD ")");
     out_string ("En");