diff --git a/atom/browser/api/lib/web-contents.coffee b/atom/browser/api/lib/web-contents.coffee
index dacbc919d665..2eda00f0689d 100644
--- a/atom/browser/api/lib/web-contents.coffee
+++ b/atom/browser/api/lib/web-contents.coffee
@@ -7,6 +7,11 @@ nextId = 0
 getNextId = -> ++nextId
 
 PDFPageSize =
+  A5:
+    custom_display_name: "A5"
+    height_microns: 210000
+    name: "ISO_A5"
+    width_microns: 148000
   A4:
     custom_display_name: "A4"
     height_microns: 297000
diff --git a/docs/api/web-contents.md b/docs/api/web-contents.md
index c35bbc9ae33c..90ecda9168be 100644
--- a/docs/api/web-contents.md
+++ b/docs/api/web-contents.md
@@ -454,6 +454,7 @@ size.
   * 1 - none
   * 2 - minimum
 * `pageSize` String - Specify page size of the generated PDF.
+  * `A5` 
   * `A4`
   * `A3`
   * `Legal`