diff --git a/core.d.ts b/core.d.ts
index dadb897f..a9378060 100644
--- a/core.d.ts
+++ b/core.d.ts
@@ -164,6 +164,7 @@ export type FileExtension =
 	| 'avro'
 	| 'icc'
 	| 'fbx'
+	| 'vsdx'
 	; // eslint-disable-line semi-style
 
 export type MimeType =
@@ -314,6 +315,7 @@ export type MimeType =
 	| 'application/avro'
 	| 'application/vnd.iccprofile'
 	| 'application/x.autodesk.fbx'
+	| 'application/vnd.visio'
 	; // eslint-disable-line semi-style
 
 export type FileTypeResult = {
diff --git a/core.js b/core.js
index bf9ee61b..bb730370 100644
--- a/core.js
+++ b/core.js
@@ -381,6 +381,11 @@ export class FileTypeParser {
 									ext: 'xlsx',
 									mime: 'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet',
 								};
+							case 'visio':
+								return {
+									ext: 'vsdx',
+									mime: 'application/vnd.visio',
+								};
 							default:
 								break;
 						}
diff --git a/fixture/fixture-vsdx.vsdx b/fixture/fixture-vsdx.vsdx
new file mode 100644
index 00000000..a4ffcfce
Binary files /dev/null and b/fixture/fixture-vsdx.vsdx differ
diff --git a/fixture/fixture-vstx.vsdx b/fixture/fixture-vstx.vsdx
new file mode 100644
index 00000000..190f1cf8
Binary files /dev/null and b/fixture/fixture-vstx.vsdx differ
diff --git a/package.json b/package.json
index 82754ef2..f54a39bf 100644
--- a/package.json
+++ b/package.json
@@ -205,7 +205,8 @@
 		"ace",
 		"avro",
 		"icc",
-		"fbx"
+		"fbx",
+		"vsdx"
 	],
 	"dependencies": {
 		"strtok3": "^8.0.0",
diff --git a/readme.md b/readme.md
index cc8f614a..e1c33d6e 100644
--- a/readme.md
+++ b/readme.md
@@ -444,7 +444,7 @@ console.log(fileType);
 - [`jxr`](https://en.wikipedia.org/wiki/JPEG_XR) - Joint Photographic Experts Group extended range
 - [`ktx`](https://www.khronos.org/opengles/sdk/tools/KTX/file_format_spec/) - OpenGL and OpenGL ES textures
 - [`lnk`](https://en.wikipedia.org/wiki/Shortcut_%28computing%29#Microsoft_Windows) - Microsoft Windows file shortcut
-- [`lz`](https://en.wikipedia.org/wiki/Lzip) - Archive file
+- [`lz`](https://en.wikipedia.org/wikihttps://en.wikipedia.org/wiki/Microsoft_Visiovsdx/Lzip) - Archive file
 - [`lzh`](https://en.wikipedia.org/wiki/LHA_(file_format)) - LZH archive
 - [`m4a`](https://en.wikipedia.org/wiki/M4A) - Audio-only MPEG-4 files
 - [`m4b`](https://en.wikipedia.org/wiki/M4B) - Audiobook and podcast MPEG-4 files, which also contain metadata including chapter markers, images, and hyperlinks
@@ -505,6 +505,7 @@ console.log(fileType);
 - [`ttf`](https://en.wikipedia.org/wiki/TrueType) - TrueType font
 - [`vcf`](https://en.wikipedia.org/wiki/VCard) - vCard
 - [`voc`](https://wiki.multimedia.cx/index.php/Creative_Voice) - Creative Voice File
+- [`vsdx`](https://en.wikipedia.org/wiki/Microsoft_Visio) - Microsoft Visio File
 - [`wasm`](https://en.wikipedia.org/wiki/WebAssembly) - WebAssembly intermediate compiled format
 - [`wav`](https://en.wikipedia.org/wiki/WAV) - Waveform Audio file
 - [`webm`](https://en.wikipedia.org/wiki/WebM) - Web video file
diff --git a/supported.js b/supported.js
index e9337823..24feb8fe 100644
--- a/supported.js
+++ b/supported.js
@@ -151,6 +151,7 @@ export const extensions = [
 	'avro',
 	'icc',
 	'fbx',
+	'vsdx',
 ];
 
 export const mimeTypes = [
@@ -301,4 +302,5 @@ export const mimeTypes = [
 	'application/avro',
 	'application/vnd.iccprofile',
 	'application/x.autodesk.fbx', // Invented by us
+	'application/vnd.visio',
 ];
diff --git a/test.js b/test.js
index fab062a7..4e25f4f2 100644
--- a/test.js
+++ b/test.js
@@ -255,6 +255,10 @@ const names = {
 		'fixture-bin',
 		'fixture-ascii',
 	],
+	vsdx: [
+		'fixture-vsdx',
+		'fixture-vstx',
+	],
 };
 
 // Define an entry here only if the file type has potential