diff --git a/CHANGELOG.md b/CHANGELOG.md
index 7884140..a1cc5e9 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,14 @@
 
 **Note that `ex_cldr_dates_times` version 2.18.0 and later are supported on Elixir 1.12 and later only.**
 
+## Cldr_Dates_Times v2.18.1
+
+This is the changelog for Cldr_Dates_Times v2.18.1 released on July 1st, 2024.  For older changelogs please consult the release tag on [GitHub](https://github.com/elixir-cldr/cldr_cldr_dates_times/tags)
+
+### Bug Fixes
+
+* Fix formatting `am/pm` with format `:narrow` or `:wide`. Thanks to @sysashi for the report. Closes #48.
+
 ## Cldr_Dates_Times v2.18.0
 
 This is the changelog for Cldr_Dates_Times v2.18.0 released on May 29th, 2024.  For older changelogs please consult the release tag on [GitHub](https://github.com/elixir-cldr/cldr_cldr_dates_times/tags)
diff --git a/lib/cldr/format/date_time_formatter.ex b/lib/cldr/format/date_time_formatter.ex
index 4dc6b2e..fb96050 100644
--- a/lib/cldr/format/date_time_formatter.ex
+++ b/lib/cldr/format/date_time_formatter.ex
@@ -1883,6 +1883,9 @@ defmodule Cldr.DateTime.Formatter do
       iex> Cldr.DateTime.Formatter.period_am_pm %{hour: 21, minute: 0}
       "PM"
 
+      iex> Cldr.DateTime.Formatter.period_am_pm %{hour: 21, minute: 0}, 5
+      "p"
+
   """
   @spec period_am_pm(Calendar.time(), integer, Keyword.t()) ::
           String.t() | {:error, String.t()}
@@ -1904,6 +1907,11 @@ defmodule Cldr.DateTime.Formatter do
 
   def period_am_pm(time, n, locale, backend, options \\ %{})
 
+  def period_am_pm(%{calendar: Calendar.ISO} = time, n, locale, backend, options) do
+    %{time | calendar: Cldr.Calendar.Gregorian}
+    |> period_am_pm(n, locale, backend, options)
+  end
+
   def period_am_pm(time, n, locale, backend, options) when n in 1..3 do
     time
     |> Cldr.Calendar.localize(:am_pm, :format, :abbreviated, backend, locale)
diff --git a/mix.exs b/mix.exs
index edfe9cc..908a70b 100644
--- a/mix.exs
+++ b/mix.exs
@@ -1,7 +1,7 @@
 defmodule Cldr.DatesTimes.Mixfile do
   use Mix.Project
 
-  @version "2.18.0"
+  @version "2.18.1"
 
   def project do
     [