diff --git a/misc/lldb_cruby.py b/misc/lldb_cruby.py
index 46fb764104..ef4820b1a5 100755
--- a/misc/lldb_cruby.py
+++ b/misc/lldb_cruby.py
@@ -507,6 +507,8 @@ def dump_node(debugger, command, ctx, result, internal_dict):
     output_string(ctx, result, dump)
 
 def rb_backtrace(debugger, command, result, internal_dict):
+    if not ('RUBY_Qfalse' in globals()):
+        lldb_init(debugger)
     bt = BackTrace(debugger, command, result, internal_dict)
     frame = bt.frame