diff --git a/instrumentation/rack/lib/opentelemetry/instrumentation/rack/middlewares/dup/event_handler.rb b/instrumentation/rack/lib/opentelemetry/instrumentation/rack/middlewares/dup/event_handler.rb
index b86b9c9710..1b3c75a08d 100644
--- a/instrumentation/rack/lib/opentelemetry/instrumentation/rack/middlewares/dup/event_handler.rb
+++ b/instrumentation/rack/lib/opentelemetry/instrumentation/rack/middlewares/dup/event_handler.rb
@@ -43,7 +43,7 @@ module Dup
           class EventHandler
             include ::Rack::Events::Abstract
 
-            OTEL_TOKEN_AND_SPAN = 'otel.rack.token_and_span'
+            OTEL_CONTEXT_INFO = 'otel.context_info'
             EMPTY_HASH = {}.freeze
 
             # Creates a server span for this current request using the incoming parent context
@@ -62,7 +62,8 @@ def on_start(request, _)
               span = create_span(parent_context, request)
               span_ctx = OpenTelemetry::Trace.context_with_span(span, parent_context: parent_context)
               rack_ctx = OpenTelemetry::Instrumentation::Rack.context_with_span(span, parent_context: span_ctx)
-              request.env[OTEL_TOKEN_AND_SPAN] = [OpenTelemetry::Context.attach(rack_ctx), span]
+              token = OpenTelemetry::Context.attach(rack_ctx)
+              request.env[OTEL_CONTEXT_INFO] = [Fiber.current, token, span]
             rescue StandardError => e
               OpenTelemetry.handle_error(exception: e)
             end
@@ -209,11 +210,17 @@ def request_span_attributes(env)
             end
 
             def detach_context(request)
-              return nil unless request.env[OTEL_TOKEN_AND_SPAN]
+              otel_context_info = request.env[OTEL_CONTEXT_INFO]
+              return unless otel_context_info
 
-              token, span = request.env[OTEL_TOKEN_AND_SPAN]
+              original_fiber, token, span = otel_context_info
               span.finish
-              OpenTelemetry::Context.detach(token)
+
+              if Fiber.current.equal?(original_fiber)
+                OpenTelemetry::Context.detach(token)
+              else
+                OpenTelemetry.logger.debug { '[rack] Skipping context detach: response processed in different fiber than request.' }
+              end
             rescue StandardError => e
               OpenTelemetry.handle_error(exception: e)
             end
diff --git a/instrumentation/rack/lib/opentelemetry/instrumentation/rack/middlewares/old/event_handler.rb b/instrumentation/rack/lib/opentelemetry/instrumentation/rack/middlewares/old/event_handler.rb
index 145cc9d034..e3cd132ae8 100644
--- a/instrumentation/rack/lib/opentelemetry/instrumentation/rack/middlewares/old/event_handler.rb
+++ b/instrumentation/rack/lib/opentelemetry/instrumentation/rack/middlewares/old/event_handler.rb
@@ -43,7 +43,7 @@ module Old
           class EventHandler
             include ::Rack::Events::Abstract
 
-            OTEL_TOKEN_AND_SPAN = 'otel.rack.token_and_span'
+            OTEL_CONTEXT_INFO = 'otel.context_info'
             EMPTY_HASH = {}.freeze
 
             # Creates a server span for this current request using the incoming parent context
@@ -62,7 +62,8 @@ def on_start(request, _)
               span = create_span(parent_context, request)
               span_ctx = OpenTelemetry::Trace.context_with_span(span, parent_context: parent_context)
               rack_ctx = OpenTelemetry::Instrumentation::Rack.context_with_span(span, parent_context: span_ctx)
-              request.env[OTEL_TOKEN_AND_SPAN] = [OpenTelemetry::Context.attach(rack_ctx), span]
+              token = OpenTelemetry::Context.attach(rack_ctx)
+              request.env[OTEL_CONTEXT_INFO] = [Fiber.current, token, span]
             rescue StandardError => e
               OpenTelemetry.handle_error(exception: e)
             end
@@ -198,11 +199,17 @@ def request_span_attributes(env)
             end
 
             def detach_context(request)
-              return nil unless request.env[OTEL_TOKEN_AND_SPAN]
+              otel_context_info = request.env[OTEL_CONTEXT_INFO]
+              return unless otel_context_info
 
-              token, span = request.env[OTEL_TOKEN_AND_SPAN]
+              original_fiber, token, span = otel_context_info
               span.finish
-              OpenTelemetry::Context.detach(token)
+
+              if Fiber.current.equal?(original_fiber)
+                OpenTelemetry::Context.detach(token)
+              else
+                OpenTelemetry.logger.debug { '[rack] Skipping context detach: response processed in different fiber than request.' }
+              end
             rescue StandardError => e
               OpenTelemetry.handle_error(exception: e)
             end
diff --git a/instrumentation/rack/lib/opentelemetry/instrumentation/rack/middlewares/stable/event_handler.rb b/instrumentation/rack/lib/opentelemetry/instrumentation/rack/middlewares/stable/event_handler.rb
index 5780aab47d..dff0dc8b5d 100644
--- a/instrumentation/rack/lib/opentelemetry/instrumentation/rack/middlewares/stable/event_handler.rb
+++ b/instrumentation/rack/lib/opentelemetry/instrumentation/rack/middlewares/stable/event_handler.rb
@@ -43,7 +43,7 @@ module Stable
           class EventHandler
             include ::Rack::Events::Abstract
 
-            OTEL_TOKEN_AND_SPAN = 'otel.rack.token_and_span'
+            OTEL_CONTEXT_INFO = 'otel.context_info'
             EMPTY_HASH = {}.freeze
 
             # Creates a server span for this current request using the incoming parent context
@@ -62,7 +62,8 @@ def on_start(request, _)
               span = create_span(parent_context, request)
               span_ctx = OpenTelemetry::Trace.context_with_span(span, parent_context: parent_context)
               rack_ctx = OpenTelemetry::Instrumentation::Rack.context_with_span(span, parent_context: span_ctx)
-              request.env[OTEL_TOKEN_AND_SPAN] = [OpenTelemetry::Context.attach(rack_ctx), span]
+              token = OpenTelemetry::Context.attach(rack_ctx)
+              request.env[OTEL_CONTEXT_INFO] = [Fiber.current, token, span]
             rescue StandardError => e
               OpenTelemetry.handle_error(exception: e)
             end
@@ -197,11 +198,17 @@ def request_span_attributes(env)
             end
 
             def detach_context(request)
-              return nil unless request.env[OTEL_TOKEN_AND_SPAN]
+              otel_context_info = request.env[OTEL_CONTEXT_INFO]
+              return unless otel_context_info
 
-              token, span = request.env[OTEL_TOKEN_AND_SPAN]
+              original_fiber, token, span = otel_context_info
               span.finish
-              OpenTelemetry::Context.detach(token)
+
+              if Fiber.current.equal?(original_fiber)
+                OpenTelemetry::Context.detach(token)
+              else
+                OpenTelemetry.logger.debug { '[rack] Skipping context detach: response processed in different fiber than request.' }
+              end
             rescue StandardError => e
               OpenTelemetry.handle_error(exception: e)
             end
diff --git a/instrumentation/rack/test/opentelemetry/instrumentation/rack/middlewares/dup/event_handler_test.rb b/instrumentation/rack/test/opentelemetry/instrumentation/rack/middlewares/dup/event_handler_test.rb
index f96ed7939c..ba2f4aeadc 100644
--- a/instrumentation/rack/test/opentelemetry/instrumentation/rack/middlewares/dup/event_handler_test.rb
+++ b/instrumentation/rack/test/opentelemetry/instrumentation/rack/middlewares/dup/event_handler_test.rb
@@ -508,4 +508,38 @@ class EventHandlerError < StandardError
       _(proxy_event).must_be_nil
     end
   end
+
+  describe 'cross-fiber context detachment' do
+    it 'finishes span without error when on_finish is called from different fiber' do
+      request = Rack::MockRequest.env_for('/')
+      rack_request = Rack::Request.new(request)
+      response = Rack::Response.new
+
+      fiber1 = Fiber.new do
+        handler.on_start(rack_request, nil)
+        Fiber.yield
+      end
+      fiber1.resume
+
+      fiber2 = Fiber.new do
+        handler.on_finish(rack_request, response)
+      end
+      fiber2.resume
+
+      _(finished_spans.size).must_equal 1
+      _(rack_span.name).must_equal 'GET'
+    end
+
+    it 'detaches context normally when same fiber' do
+      request = Rack::MockRequest.env_for('/')
+      rack_request = Rack::Request.new(request)
+      response = Rack::Response.new
+
+      handler.on_start(rack_request, nil)
+      handler.on_finish(rack_request, response)
+
+      _(finished_spans.size).must_equal 1
+      _(rack_span.name).must_equal 'GET'
+    end
+  end
 end
diff --git a/instrumentation/rack/test/opentelemetry/instrumentation/rack/middlewares/old/event_handler_test.rb b/instrumentation/rack/test/opentelemetry/instrumentation/rack/middlewares/old/event_handler_test.rb
index b983921e0c..429b5bb936 100644
--- a/instrumentation/rack/test/opentelemetry/instrumentation/rack/middlewares/old/event_handler_test.rb
+++ b/instrumentation/rack/test/opentelemetry/instrumentation/rack/middlewares/old/event_handler_test.rb
@@ -483,4 +483,38 @@ class EventHandlerError < StandardError
       _(proxy_event).must_be_nil
     end
   end
+
+  describe 'cross-fiber context detachment' do
+    it 'finishes span without error when on_finish is called from different fiber' do
+      request = Rack::MockRequest.env_for('/')
+      rack_request = Rack::Request.new(request)
+      response = Rack::Response.new
+
+      fiber1 = Fiber.new do
+        handler.on_start(rack_request, nil)
+        Fiber.yield
+      end
+      fiber1.resume
+
+      fiber2 = Fiber.new do
+        handler.on_finish(rack_request, response)
+      end
+      fiber2.resume
+
+      _(finished_spans.size).must_equal 1
+      _(rack_span.name).must_equal 'HTTP GET'
+    end
+
+    it 'detaches context normally when same fiber' do
+      request = Rack::MockRequest.env_for('/')
+      rack_request = Rack::Request.new(request)
+      response = Rack::Response.new
+
+      handler.on_start(rack_request, nil)
+      handler.on_finish(rack_request, response)
+
+      _(finished_spans.size).must_equal 1
+      _(rack_span.name).must_equal 'HTTP GET'
+    end
+  end
 end
diff --git a/instrumentation/rack/test/opentelemetry/instrumentation/rack/middlewares/stable/event_handler_test.rb b/instrumentation/rack/test/opentelemetry/instrumentation/rack/middlewares/stable/event_handler_test.rb
index 0316898226..456de4b815 100644
--- a/instrumentation/rack/test/opentelemetry/instrumentation/rack/middlewares/stable/event_handler_test.rb
+++ b/instrumentation/rack/test/opentelemetry/instrumentation/rack/middlewares/stable/event_handler_test.rb
@@ -479,4 +479,38 @@ class EventHandlerError < StandardError
       _(proxy_event).must_be_nil
     end
   end
+
+  describe 'cross-fiber context detachment' do
+    it 'finishes span without error when on_finish is called from different fiber' do
+      request = Rack::MockRequest.env_for('/')
+      rack_request = Rack::Request.new(request)
+      response = Rack::Response.new
+
+      fiber1 = Fiber.new do
+        handler.on_start(rack_request, nil)
+        Fiber.yield
+      end
+      fiber1.resume
+
+      fiber2 = Fiber.new do
+        handler.on_finish(rack_request, response)
+      end
+      fiber2.resume
+
+      _(finished_spans.size).must_equal 1
+      _(rack_span.name).must_equal 'GET'
+    end
+
+    it 'detaches context normally when same fiber' do
+      request = Rack::MockRequest.env_for('/')
+      rack_request = Rack::Request.new(request)
+      response = Rack::Response.new
+
+      handler.on_start(rack_request, nil)
+      handler.on_finish(rack_request, response)
+
+      _(finished_spans.size).must_equal 1
+      _(rack_span.name).must_equal 'GET'
+    end
+  end
 end