diff --git a/activesupport/lib/active_support/core_ext/kernel/reporting.rb b/activesupport/lib/active_support/core_ext/kernel/reporting.rb
index 79d3303b41..36ab836457 100644
--- a/activesupport/lib/active_support/core_ext/kernel/reporting.rb
+++ b/activesupport/lib/active_support/core_ext/kernel/reporting.rb
@@ -91,6 +91,7 @@ module Kernel
     stream_io.rewind
     return captured_stream.read
   ensure
+    captured_stream.close
     captured_stream.unlink
     stream_io.reopen(origin_stream)
   end