diff --git a/base/scripts/rc.tb b/base/scripts/rc.tb
index 74e6f70..ea26b4c 100644
--- a/base/scripts/rc.tb
+++ b/base/scripts/rc.tb
@@ -1 +1,2 @@
 @mkalias pctl base:/bin/pctl
+@mkalias tb base:/bin/tb
diff --git a/user/tb/runtime.c b/user/tb/runtime.c
index 3903a82..94d636c 100644
--- a/user/tb/runtime.c
+++ b/user/tb/runtime.c
@@ -36,9 +36,8 @@ bool rt_mkalias(Token *tks) {
   while (tk) {
     if (i == 0) {
       usprintf(alias->namebuf, "%.*s", (int)tk->len, tk->ptr);
-    } else {
-      size_t off = string_len(alias->valbuf);
-      usprintf(alias->valbuf + off, "%.*s", (int)tk->len, tk->ptr);
+    } else if (i == 1) {
+      usprintf(alias->valbuf, "%.*s", (int)tk->len, tk->ptr);
     }
     i++;
     tk = tk->next;