diff --git a/README.md b/README.md
index 96b01db4..56cef249 100644
--- a/README.md
+++ b/README.md
@@ -2628,8 +2628,8 @@ Set the page margin (or override the preset) given an attribute name and a value
 #### sheet.pageMarginsPreset() ⇒ <code>string</code>
 Page margins preset is a set of page margins associated with a name.
 The page margin preset acts as a fallback when not explicitly defined by `Sheet.pageMargins`.
-If a sheet already contains page margins, they are defined as the "template" preset.
-Otherwise the preset is undefined and will not be including in the output of `Sheet.toXmls`.
+If a sheet already contains page margins, it attempts to auto-detect, otherwise they are defined as the template preset.
+If no page margins exist, then the preset is undefined and will not be included in the output of `Sheet.toXmls`.
 Available presets include: normal, wide, narrow, template.
 
 Get the page margins preset name. The registered name of a predefined set of attributes.
diff --git a/lib/Sheet.js b/lib/Sheet.js
index 99a97981..80e6c812 100644
--- a/lib/Sheet.js
+++ b/lib/Sheet.js
@@ -1007,8 +1007,8 @@ class Sheet {
     /**
      * Page margins preset is a set of page margins associated with a name.
      * The page margin preset acts as a fallback when not explicitly defined by `Sheet.pageMargins`.
-     * If a sheet already contains page margins, they are defined as the "template" preset.
-     * Otherwise the preset is undefined and will not be including in the output of `Sheet.toXmls`.
+     * If a sheet already contains page margins, it attempts to auto-detect, otherwise they are defined as the template preset.
+     * If no page margins exist, then the preset is undefined and will not be included in the output of `Sheet.toXmls`.
      * Available presets include: normal, wide, narrow, template.
      *
      * Get the page margins preset name. The registered name of a predefined set of attributes.