diff --git a/app/assets/icon/master_file.png b/app/assets/icon/master_file.png
new file mode 100644
index 0000000..f79a513
Binary files /dev/null and b/app/assets/icon/master_file.png differ
diff --git a/app/assets/icon/md-file-icon.svg b/app/assets/icon/md-file-icon.svg
new file mode 100644
index 0000000..816df71
--- /dev/null
+++ b/app/assets/icon/md-file-icon.svg
@@ -0,0 +1 @@
+<svg id="Icon_v4" data-name="Icon v4" xmlns="http://www.w3.org/2000/svg" viewBox="0 0 738.9 983.21"><defs><style>.cls-1,.cls-4,.cls-5{fill:#fff;}.cls-1,.cls-3{stroke:gray;stroke-miterlimit:10;stroke-width:6px;}.cls-2{fill:#ccc;}.cls-3{fill:none;}.cls-5{isolation:isolate;font-size:356.4px;font-family:Arial-BoldMT, Arial;font-weight:700;}</style></defs><polygon class="cls-1" points="528.18 3 3 3 3 980.21 735.9 980.21 735.9 210.72 528.18 3"/><polygon class="cls-2" points="528.18 210.72 735.9 210.72 528.18 3 528.18 210.72"/><line class="cls-3" x1="528.18" y1="3" x2="528.18" y2="210.72"/><line class="cls-3" x1="528.18" y1="210.72" x2="735.9" y2="210.72"/><path class="cls-2" d="M622.1,336h-327a35.79,35.79,0,1,1,0-71.57H622.1a35.79,35.79,0,1,1,0,71.57Z" transform="translate(-170.55 -48.4)"/><path class="cls-2" d="M496.89,206.43H295.75c-20.06,0-36.87-16.42-36.48-36.49a35.77,35.77,0,0,1,35.78-35.08h201.1c20.08,0,36.92,16.43,36.52,36.51A35.79,35.79,0,0,1,496.89,206.43Z" transform="translate(-170.55 -48.4)"/><path class="cls-2" d="M751.64,940.15H295.05a35.79,35.79,0,1,1,0-71.57H751.64a35.79,35.79,0,1,1,0,71.57Z" transform="translate(-170.55 -48.4)"/><rect x="6.27" y="360.89" width="726.27" height="386.13"/><path id="path3711" class="cls-4" d="M833,647l-42.78,41.65-42.78,41.64-44.8-41-44.8-41,87.58-.63Z" transform="translate(-170.55 -48.4)"/><rect id="rect3715" class="cls-4" x="542" y="426" width="65.65" height="174.09"/><text class="cls-5" transform="translate(76.5 681.4) scale(1.35 1)">M</text></svg>
\ No newline at end of file
diff --git a/app/assets/icon/md_file.icns b/app/assets/icon/md_file.icns
new file mode 100644
index 0000000..3e3cf6b
Binary files /dev/null and b/app/assets/icon/md_file.icns differ
diff --git a/app/assets/icon/md_file.ico b/app/assets/icon/md_file.ico
new file mode 100644
index 0000000..5bf46b6
Binary files /dev/null and b/app/assets/icon/md_file.ico differ
diff --git a/build/deployConfig.js b/build/deployConfig.js
index 6f236cc..040d7a8 100644
--- a/build/deployConfig.js
+++ b/build/deployConfig.js
@@ -2,6 +2,8 @@ const APPLICATION_NAME = "Markdown Viewer"
 const APPLICATION_SHORTNAME = "mdview"
 const WIN_ICON = "app/assets/icon/md.ico"
 const MAC_ICON = "app/assets/icon/md.icns"
+const DOCUMENT_ICON = "app/assets/icon/md_file" // Electron-builder appends .icns .ico automatically
+
 const RESPOURCE_FILES = ["README.md", "CONTRIBUTING.md", "CHANGELOG.md", "LICENSE", "doc/**"]
 
 module.exports = {
@@ -66,13 +68,13 @@ module.exports = {
     fileAssociations: [
         {
             name: "Markdown file",
-            ext: ".md",
-            icon: WIN_ICON,
+            ext: "md",
+            icon: DOCUMENT_ICON,
         },
         {
             name: "Markdown file",
-            ext: ".markdown",
-            icon: WIN_ICON,
+            ext: "markdown",
+            icon: DOCUMENT_ICON,
         },
     ],
 }