diff --git a/lib/diver_down/trace/session.rb b/lib/diver_down/trace/session.rb
index c73c2a1..a3b1291 100644
--- a/lib/diver_down/trace/session.rb
+++ b/lib/diver_down/trace/session.rb
@@ -38,13 +38,15 @@ def stop
       private
 
       def build_trace_point
-        call_stack = DiverDown::Trace::CallStack.new
+        call_stacks = {}
 
         TracePoint.new(*DiverDown::Trace::Tracer.trace_events) do |tp|
           # Skip the trace of the library itself
           next if tp.path&.start_with?(DiverDown::LIB_DIR)
           next if TracePoint == tp.defined_class
 
+          call_stack = call_stacks[Thread.current] ||= DiverDown::Trace::CallStack.new
+
           case tp.event
           when :b_call
             call_stack.push