diff --git a/benchmarks/lobsters/benchmark.rb b/benchmarks/lobsters/benchmark.rb
index 240c50c9..3a28fe81 100644
--- a/benchmarks/lobsters/benchmark.rb
+++ b/benchmarks/lobsters/benchmark.rb
@@ -47,6 +47,7 @@
       puts response_array.inspect
       raise "HTTP status is #{response_array.first} instead of 200 for req #{idx}/#{generator.routes.size}, #{path.inspect}. Is the benchmark app properly set up? See README.md."
     end
+    response_array.last.close # Response might be a Rack::BodyProxy and MUST be closed.
   end
 end
 
diff --git a/benchmarks/railsbench/benchmark.rb b/benchmarks/railsbench/benchmark.rb
index 20a83020..89561d48 100644
--- a/benchmarks/railsbench/benchmark.rb
+++ b/benchmarks/railsbench/benchmark.rb
@@ -29,6 +29,7 @@
     unless response_array.first == 200
       raise "HTTP response is #{response_array.first} instead of 200. Is the benchmark app properly set up? See README.md."
     end
+    response_array.last.close # Response might be a Rack::BodyProxy and MUST be closed.
   end
 end
 
diff --git a/benchmarks/railsbench/popular_lines.rb b/benchmarks/railsbench/popular_lines.rb
index fdb4397e..616cda08 100644
--- a/benchmarks/railsbench/popular_lines.rb
+++ b/benchmarks/railsbench/popular_lines.rb
@@ -22,6 +22,7 @@ def run_bench(app, visiting_routes)
       p response_array
       raise "HTTP response is #{response_array.first} instead of 200. Is the benchmark app properly set up? See README.md."
     end
+    response_array.last.close # Response might be a Rack::BodyProxy and MUST be closed.
   end
 end
 
diff --git a/benchmarks/railsbench/popular_methods.rb b/benchmarks/railsbench/popular_methods.rb
index 25de1557..507e6a87 100644
--- a/benchmarks/railsbench/popular_methods.rb
+++ b/benchmarks/railsbench/popular_methods.rb
@@ -20,6 +20,7 @@ def run_bench(app, visiting_routes)
       p response_array
       raise "HTTP response is #{response_array.first} instead of 200. Is the benchmark app properly set up? See README.md."
     end
+    response_array.last.close # Response might be a Rack::BodyProxy and MUST be closed.
   end
 end