diff --git a/.gitattributes b/.gitattributes
index 0a94073..2136101 100644
--- a/.gitattributes
+++ b/.gitattributes
@@ -42,3 +42,4 @@
 *.aac binary
 *.wma binary
 *.au binary
+*.rmi binary
diff --git a/src/AudioFormat.php b/src/AudioFormat.php
index a20e8f9..b87f807 100644
--- a/src/AudioFormat.php
+++ b/src/AudioFormat.php
@@ -20,4 +20,5 @@ final class AudioFormat
     public const AAC = 'aac';
     public const WMA = 'wma';
     public const AU = 'au';
+    public const RMI = 'rmi';
 }
diff --git a/src/AudioMimeType.php b/src/AudioMimeType.php
index 45c5d07..602895e 100644
--- a/src/AudioMimeType.php
+++ b/src/AudioMimeType.php
@@ -20,4 +20,5 @@ final class AudioMimeType
     public const AUDIO_AAC = 'audio/aac';
     public const AUDIO_WMA = 'audio/x-ms-wma';
     public const AUDIO_AU = 'audio/basic';
+    public const AUDIO_RMI = 'audio/midi';
 }
diff --git a/src/Detector/RmiDetector.php b/src/Detector/RmiDetector.php
new file mode 100644
index 0000000..8d64ee2
--- /dev/null
+++ b/src/Detector/RmiDetector.php
@@ -0,0 +1,33 @@
+<?php
+
+namespace Selective\AudioType\Detector;
+
+use Selective\AudioType\AudioFormat;
+use Selective\AudioType\AudioMimeType;
+use Selective\AudioType\AudioType;
+use SplFileObject;
+
+/**
+ * Detector.
+ */
+final class RmiDetector implements AudioDetectorInterface
+{
+    /**
+     * Detect RMI, RIFF-MIDI audio format.
+     *
+     * @param SplFileObject $file The audio file
+     *
+     * @return AudioType|null The audio type
+     */
+    public function detect(SplFileObject $file): ?AudioType
+    {
+        $magicNumber = (string)$file->fread(4);
+        $header = (string)$file->fread(25);
+        $hasIdentifiedHeader = strpos($header, 'RMIDdata') !== false || strpos($header, 'MThd') !== false;
+
+        return $magicNumber === 'RIFF' && $hasIdentifiedHeader ? new AudioType(
+            AudioFormat::RMI,
+            AudioMimeType::AUDIO_RMI
+        ) : null;
+    }
+}
diff --git a/src/Provider/DefaultAudioProvider.php b/src/Provider/DefaultAudioProvider.php
index 841de81..2beb0aa 100644
--- a/src/Provider/DefaultAudioProvider.php
+++ b/src/Provider/DefaultAudioProvider.php
@@ -15,6 +15,7 @@
 use Selective\AudioType\Detector\AacDetector;
 use Selective\AudioType\Detector\WmaDetector;
 use Selective\AudioType\Detector\AuDetector;
+use Selective\AudioType\Detector\RmiDetector;
 
 /**
  * All supported audio formats.
@@ -40,6 +41,7 @@ public function getDetectors(): array
             new AacDetector(),
             new WmaDetector(),
             new AuDetector(),
+            new RmiDetector(),
         ];
     }
 }
diff --git a/tests/AudioTypeDetectorTest.php b/tests/AudioTypeDetectorTest.php
index 3f8aacf..cd518d0 100644
--- a/tests/AudioTypeDetectorTest.php
+++ b/tests/AudioTypeDetectorTest.php
@@ -76,6 +76,7 @@ public function providerGetAudioTypeFromFile(): array
             'AAC' => [__DIR__ . '/files/test.aac', AudioFormat::AAC, AudioMimeType::AUDIO_AAC],
             'WMA' => [__DIR__ . '/files/test.wma', AudioFormat::WMA, AudioMimeType::AUDIO_WMA],
             'AU' => [__DIR__ . '/files/test.au', AudioFormat::AU, AudioMimeType::AUDIO_AU],
+            'RMI' => [__DIR__ . '/files/test.rmi', AudioFormat::RMI, AudioMimeType::AUDIO_RMI],
         ];
     }
 
diff --git a/tests/files/test.rmi b/tests/files/test.rmi
new file mode 100644
index 0000000..b961c2f
Binary files /dev/null and b/tests/files/test.rmi differ