diff --git a/lib/mimetype.php b/lib/mimetype.php
index c002d3396..525d5f21b 100644
--- a/lib/mimetype.php
+++ b/lib/mimetype.php
@@ -15,6 +15,7 @@ class Mimetype {
     const TAR_TYPE = "application/x-tar";
     const ZIP_TYPE = "application/zip";
     const RAR_TYPE = "application/x-rar-compressed";
+    const KEYNOTE_TYPE = "application/vnd.apple.keynote";
 
     const FLAG_INLINE = 1;
     const FLAG_UTF8 = 2;
@@ -40,6 +41,7 @@ class Mimetype {
         self::PDF_TYPE =>     [".pdf", "PDF", self::FLAG_INLINE | self::FLAG_REQUIRE_SNIFF],
         self::PS_TYPE =>      [".ps", "PostScript", self::FLAG_COMPRESSIBLE],
         self::PPT_TYPE =>     [".ppt", "PowerPoint", self::FLAG_INCOMPRESSIBLE, "application/mspowerpoint", "application/powerpoint", "application/x-mspowerpoint"],
+        self::KEYNOTE_TYPE => [".key", "Keynote", self::FLAG_INCOMPRESSIBLE, "application/x-iwork-keynote-sffkey"],
         "application/vnd.openxmlformats-officedocument.presentationml.presentation" =>
                               [".pptx", "PowerPoint", self::FLAG_INCOMPRESSIBLE],
         "video/mp4" =>        [".mp4", null, self::FLAG_INCOMPRESSIBLE],
diff --git a/src/paperoption.php b/src/paperoption.php
index 804acd9b9..8f63eec3c 100644
--- a/src/paperoption.php
+++ b/src/paperoption.php
@@ -1316,7 +1316,8 @@ function mimetypes() {
         } else if ($this->type === "slides") {
             return [Mimetype::checked_lookup(".pdf"),
                     Mimetype::checked_lookup(".ppt"),
-                    Mimetype::checked_lookup(".pptx")];
+                    Mimetype::checked_lookup(".pptx"),
+                    Mimetype::checked_lookup(".key")];
         } else if ($this->type === "video") {
             return [Mimetype::checked_lookup(".mp4"),
                     Mimetype::checked_lookup(".avi")];