diff --git a/gdbstub.c b/gdbstub.c
index 8363683852..b470aec8ea 100644
--- a/gdbstub.c
+++ b/gdbstub.c
@@ -1673,12 +1673,23 @@ static void handle_remove_bp(GdbCmdContext *gdb_ctx, void *user_ctx)
     put_packet(gdb_ctx->s, "E22");
 }
 
+/*
+ * handle_set/get_reg
+ *
+ * Older gdb are really dumb, and don't use 'G/g' if 'P/p' is available.
+ * This works, but can be very slow. Anything new enough to understand
+ * XML also knows how to use this properly. However to use this we
+ * need to define a local XML file as well as be talking to a
+ * reasonably modern gdb. Responding with an empty packet will cause
+ * the remote gdb to fallback to older methods.
+ */
+
 static void handle_set_reg(GdbCmdContext *gdb_ctx, void *user_ctx)
 {
     int reg_size;
 
     if (!gdb_has_xml) {
-        put_packet(gdb_ctx->s, "E00");
+        put_packet(gdb_ctx->s, "");
         return;
     }
 
@@ -1698,11 +1709,6 @@ static void handle_get_reg(GdbCmdContext *gdb_ctx, void *user_ctx)
 {
     int reg_size;
 
-    /*
-     * Older gdb are really dumb, and don't use 'g' if 'p' is avaialable.
-     * This works, but can be very slow.  Anything new enough to
-     * understand XML also knows how to use this properly.
-     */
     if (!gdb_has_xml) {
         put_packet(gdb_ctx->s, "");
         return;