diff --git a/README.md b/README.md
index 1eb1d16..37f2103 100644
--- a/README.md
+++ b/README.md
@@ -10,7 +10,7 @@ pairing with smart people at Hashrocket.
 
 For a steady stream of TILs, [sign up for my newsletter](https://crafty-builder-6996.ck.page/e169c61186).
 
-_1592 TILs and counting..._
+_1593 TILs and counting..._
 
 See some of the other learning resources I work on:
 - [Ruby Operator Lookup](https://www.visualmode.dev/ruby-operators)
@@ -1319,6 +1319,7 @@ See some of the other learning resources I work on:
 - [Named Regex Captures Are Assigned To Variables](ruby/named-regex-captures-are-assigned-to-variables.md)
 - [Navigate Back In The Browser With Capybara](ruby/navigate-back-in-the-browser-with-capybara.md)
 - [Next And Previous Floats](ruby/next-and-previous-floats.md)
+- [OpenStruct Has Bad Performance Characteristics](ruby/open-struct-has-bad-performance-characteristics.md)
 - [Or Operator Precedence](ruby/or-operator-precedence.md)
 - [Output Bytecode For A Ruby Program](ruby/output-bytecode-for-a-ruby-program.md)
 - [Override The Initial Sequence Value](ruby/override-the-initial-sequence-value.md)
diff --git a/ruby/open-struct-has-bad-performance-characteristics.md b/ruby/open-struct-has-bad-performance-characteristics.md
new file mode 100644
index 0000000..936b4c7
--- /dev/null
+++ b/ruby/open-struct-has-bad-performance-characteristics.md
@@ -0,0 +1,32 @@
+# OpenStruct Has Bad Performance Characteristics
+
+The Ruby docs for `OpenStruct` have a [_Caveats_
+section](https://ruby-doc.org/3.4.1/stdlibs/ostruct/OpenStruct.html#class-OpenStruct-label-Caveats)
+that warns about the poor performance characteristics of `OpenStruct` relative
+to `Struct` and `Hash`.
+
+> This should be a consideration if there is a concern about the performance of
+> the objects that are created, as there is much more overhead in the setting
+> of these properties compared to using a Hash or a Struct. Creating an open
+> struct from a small Hash and accessing a few of the entries can be 200 times
+> slower than accessing the hash directly.
+
+This doesn't mean don't use `OpenStruct`, but do be aware of if you are using
+it in a hot path or if you are allocating and processing tons of them.
+
+If you turn on _Performance Warnings_ in Ruby, you'll see a warning message
+when allocating an `OpenStruct`.
+
+```ruby
+> require 'ostruct'
+=> true
+> os1 = OpenStruct.new
+=> #<OpenStruct>
+> Warning[:performance] = true
+=> true
+> os2 = OpenStruct.new
+(irb):6: warning: OpenStruct use is discouraged for performance reasons
+=> #<OpenStruct>
+```
+
+[source](https://www.reddit.com/r/ruby/comments/1d54mwl/comment/l6jgn59/)