diff --git a/sentry-ruby/lib/sentry/hub.rb b/sentry-ruby/lib/sentry/hub.rb
index 535dafbe1..5f99edb71 100644
--- a/sentry-ruby/lib/sentry/hub.rb
+++ b/sentry-ruby/lib/sentry/hub.rb
@@ -249,7 +249,7 @@ def capture_metric(name:, type:, value:, unit: nil, attributes: nil)
         value: value,
         type: type,
         unit: unit,
-        attributes: attributes,
+        attributes: attributes&.dup,
       )
 
       current_client.buffer_metric_event(metric, current_scope)