diff --git a/actionpack/lib/action_controller/caching/fragments.rb b/actionpack/lib/action_controller/caching/fragments.rb
index e4f5de44abc1a378a8d35fc3c62c3afc5fc555a6..57b31ec9d1b84a211a74582da09f3489aab442c9 100644
--- a/actionpack/lib/action_controller/caching/fragments.rb
+++ b/actionpack/lib/action_controller/caching/fragments.rb
@@ -61,16 +61,18 @@ def fragment_cache_key(key)
       end
 
       def fragment_for(block, name = {}, options = nil) #:nodoc:
-        unless perform_caching then block.call; return end
-
-        buffer = yield
-
-        if cache = read_fragment(name, options)
-          buffer.concat(cache)
+        if perform_caching
+          buffer = yield
+
+          if cache = read_fragment(name, options)
+            buffer.concat(cache)
+          else
+            pos = buffer.length
+            block.call
+            write_fragment(name, buffer[pos..-1], options)
+          end
         else
-          pos = buffer.length
           block.call
-          write_fragment(name, buffer[pos..-1], options)
         end
       end
 
diff --git a/actionpack/lib/action_view/template_handlers/erb.rb b/actionpack/lib/action_view/template_handlers/erb.rb
index 458416b6cbabde9ca4dbc0f3891ddad76010b1ae..ac715e30c2ddae8a6501c5d86b7d5a1ec00d2a11 100644
--- a/actionpack/lib/action_view/template_handlers/erb.rb
+++ b/actionpack/lib/action_view/template_handlers/erb.rb
@@ -53,7 +53,9 @@ def compile(template)
       end
 
       def cache_fragment(block, name = {}, options = nil) #:nodoc:
-        @view.fragment_for(block, name, options) { @view.response.template.output_buffer ||= '' }
+        @view.fragment_for(block, name, options) do
+          @view.response.template.output_buffer
+        end
       end
     end
   end