diff --git a/lib/cooked_post_processor.rb b/lib/cooked_post_processor.rb
index 938c8fbeb19..a73f65f41f0 100644
--- a/lib/cooked_post_processor.rb
+++ b/lib/cooked_post_processor.rb
@@ -23,7 +23,8 @@ class CookedPostProcessor
     @cooking_options[:topic_id] = post.topic_id
     @cooking_options = @cooking_options.symbolize_keys
 
-    @doc = Nokogiri::HTML::fragment(post.cook(post.raw, @cooking_options))
+    cooked = post.cook(post.raw, @cooking_options)
+    @doc = Nokogiri::HTML::fragment(cooked)
     @has_oneboxes = post.post_analyzer.found_oneboxes?
     @size_cache = {}
 
diff --git a/lib/oneboxer.rb b/lib/oneboxer.rb
index 1c2e9998944..9c323f0c391 100644
--- a/lib/oneboxer.rb
+++ b/lib/oneboxer.rb
@@ -116,7 +116,11 @@ module Oneboxer
     end
 
     # strip empty <p> elements
-    doc.css("p").each { |p| p.remove if p.children.empty? }
+    doc.css("p").each do |p|
+      if p.children.empty? && doc.children.count > 1
+        p.remove
+      end
+    end
 
     Result.new(doc, changed)
   end
diff --git a/spec/components/cooked_post_processor_spec.rb b/spec/components/cooked_post_processor_spec.rb
index 4a9165d5b6e..9e23a18a92b 100644
--- a/spec/components/cooked_post_processor_spec.rb
+++ b/spec/components/cooked_post_processor_spec.rb
@@ -1783,6 +1783,13 @@ describe CookedPostProcessor do
       expect(reply.raw).to eq(raw)
     end
 
+    it "does not generate a blank HTML document" do
+      post = Fabricate(:post, topic: topic, raw: "<sunday><monday>")
+      cp = CookedPostProcessor.new(post)
+      cp.post_process
+      expect(cp.html).to eq("<p></p>")
+    end
+
     it "works only on new posts" do
       Fabricate(:post, topic: topic, hidden: true, raw: "this is the second post after")
       Fabricate(:post, topic: topic, post_type: Post.types[:small_action])