diff --git a/src/MediaType.php b/src/MediaType.php
index 0ae1b76c..32d1e6e5 100644
--- a/src/MediaType.php
+++ b/src/MediaType.php
@@ -25,6 +25,7 @@ enum MediaType: string
     case IMAGE_X_WINDOWS_BMP = 'image/x-windows-bmp';
     case IMAGE_X_WIN_BITMAP = 'image/x-win-bitmap';
     case IMAGE_X_XBITMAP = 'image/x-xbitmap';
+    case IMAGE_X_BMP3 = 'image/x-bmp3';
     case IMAGE_TIFF = 'image/tiff';
     case IMAGE_JP2 = 'image/jp2';
     case IMAGE_X_JP2_CODESTREAM = 'image/x-jp2-codestream';
@@ -60,6 +61,7 @@ public function format(): Format
             self::IMAGE_X_MS_BMP,
             self::IMAGE_X_XBITMAP,
             self::IMAGE_X_WINDOWS_BMP,
+            self::IMAGE_X_BMP3,
             self::IMAGE_X_WIN_BITMAP => Format::BMP,
             self::IMAGE_TIFF => Format::TIFF,
             self::IMAGE_JP2,
diff --git a/tests/Unit/FileExtensionTest.php b/tests/Unit/FileExtensionTest.php
index b7d3fd08..04f7c917 100644
--- a/tests/Unit/FileExtensionTest.php
+++ b/tests/Unit/FileExtensionTest.php
@@ -104,7 +104,7 @@ public static function mediaTypesDataProvider(): Generator
         yield [FileExtension::GIF, 1, MediaType::IMAGE_GIF];
         yield [FileExtension::PNG, 2, MediaType::IMAGE_PNG];
         yield [FileExtension::AVIF, 2, MediaType::IMAGE_AVIF];
-        yield [FileExtension::BMP, 8, MediaType::IMAGE_BMP];
+        yield [FileExtension::BMP, 9, MediaType::IMAGE_BMP];
         yield [FileExtension::TIFF, 1, MediaType::IMAGE_TIFF];
         yield [FileExtension::TIF, 1, MediaType::IMAGE_TIFF];
         yield [FileExtension::JP2, 4, MediaType::IMAGE_JP2];
diff --git a/tests/Unit/FormatTest.php b/tests/Unit/FormatTest.php
index 96b87d19..dc8274df 100644
--- a/tests/Unit/FormatTest.php
+++ b/tests/Unit/FormatTest.php
@@ -107,7 +107,7 @@ public function testMediaTypesBmp(): void
         $format = Format::BMP;
         $mediaTypes = $format->mediaTypes();
         $this->assertIsArray($mediaTypes);
-        $this->assertCount(8, $mediaTypes);
+        $this->assertCount(9, $mediaTypes);
 
         $this->assertEquals(MediaType::IMAGE_BMP, $format->mediaType());
     }
diff --git a/tests/Unit/MediaTypeTest.php b/tests/Unit/MediaTypeTest.php
index db00c5ff..32fb8364 100644
--- a/tests/Unit/MediaTypeTest.php
+++ b/tests/Unit/MediaTypeTest.php
@@ -79,6 +79,9 @@ public function testFormatBmp(): void
 
         $mime = MediaType::IMAGE_X_WINDOWS_BMP;
         $this->assertEquals(Format::BMP, $mime->format());
+
+        $mime = MediaType::IMAGE_X_BMP3;
+        $this->assertEquals(Format::BMP, $mime->format());
     }
 
     public function testFormatTiff(): void
@@ -142,6 +145,7 @@ public static function fileExtensionsDataProvider(): Generator
         yield [MediaType::IMAGE_X_WINDOWS_BMP, 1, FileExtension::BMP];
         yield [MediaType::IMAGE_X_WIN_BITMAP, 1, FileExtension::BMP];
         yield [MediaType::IMAGE_X_XBITMAP, 1, FileExtension::BMP];
+        yield [MediaType::IMAGE_X_BMP3, 1, FileExtension::BMP];
         yield [MediaType::IMAGE_TIFF, 2, FileExtension::TIF];
         yield [MediaType::IMAGE_JP2, 9, FileExtension::JP2];
         yield [MediaType::IMAGE_JPX, 9, FileExtension::JP2];