diff --git a/backend/src/main/kotlin/dev/twango/jetplay/transcode/MediaTranscoder.kt b/backend/src/main/kotlin/dev/twango/jetplay/transcode/MediaTranscoder.kt
index 7ec6a445..44cfec3b 100644
--- a/backend/src/main/kotlin/dev/twango/jetplay/transcode/MediaTranscoder.kt
+++ b/backend/src/main/kotlin/dev/twango/jetplay/transcode/MediaTranscoder.kt
@@ -33,8 +33,7 @@ object MediaTranscoder {
         "pcma" to RawAudioHint("alaw", 8000, 1),
         "alaw" to RawAudioHint("alaw", 8000, 1),
         "g722" to RawAudioHint("g722", 16000, 1),
-        "gsm" to RawAudioHint("gsm", 8000, 1),
-        "sln" to RawAudioHint("s16le", 8000, 1),
+        "slin" to RawAudioHint("s16le", 8000, 1),
     )
 
     /** Must stay in sync with the shared classifier. */
diff --git a/frontend/src/main/resources/dev.twango.jetplay.frontend.xml b/frontend/src/main/resources/dev.twango.jetplay.frontend.xml
index 2c9c10f9..b39d2156 100644
--- a/frontend/src/main/resources/dev.twango.jetplay.frontend.xml
+++ b/frontend/src/main/resources/dev.twango.jetplay.frontend.xml
@@ -7,7 +7,7 @@
         <fileType name="Media"
                   implementationClass="dev.twango.jetplay.editor.MediaFileType"
                   fieldName="INSTANCE"
-                  extensions="mp4;m4v;mkv;avi;mov;wmv;flv;webm;ogv;mts;m2ts;m2t;3gp;ivf;mp3;wav;ogg;oga;opus;m4a;aac;wma;aiff;aif;flac;ac3;eac3;caf;adts;amr;au;pcmu;ulaw;pcma;alaw;g722;gsm;sln"/>
+                  extensions="mp4;m4v;mkv;avi;mov;wmv;flv;webm;ogv;m2ts;m2t;3gp;ivf;mp3;wav;ogg;oga;opus;m4a;aac;wma;aiff;aif;flac;ac3;eac3;caf;adts;amr;au;pcmu;ulaw;pcma;alaw;g722;slin"/>
         <fileIconProvider implementation="dev.twango.jetplay.editor.MediaFileIconProvider"/>
         <fileEditorProvider implementation="dev.twango.jetplay.editor.MediaFileEditorProvider"/>
         <notificationGroup id="JetPlay" displayType="BALLOON"/>
diff --git a/shared/src/main/kotlin/dev/twango/jetplay/media/MediaClassification.kt b/shared/src/main/kotlin/dev/twango/jetplay/media/MediaClassification.kt
index 0c140d97..d9af2a6a 100644
--- a/shared/src/main/kotlin/dev/twango/jetplay/media/MediaClassification.kt
+++ b/shared/src/main/kotlin/dev/twango/jetplay/media/MediaClassification.kt
@@ -3,7 +3,7 @@ package dev.twango.jetplay.media
 object MediaClassification {
 
     // Video extensions registered by the media file type in the frontend descriptor.
-    // .ts is excluded to avoid clobbering TypeScript files.
+    // .ts and .mts are excluded to avoid clobbering TypeScript files.
     private val VIDEO_EXTENSIONS = setOf(
         "mp4",
         "m4v",
@@ -14,7 +14,6 @@ object MediaClassification {
         "flv",
         "webm",
         "ogv",
-        "mts",
         "m2ts",
         "m2t",
         "3gp",
@@ -34,14 +33,14 @@ object MediaClassification {
     )
 
     // Headerless raw codec streams that need explicit demuxer hints.
+    // Signed-linear uses .slin not .sln to avoid clashing with Visual Studio solution files.
     val rawAudioExtensions: Set<String> = setOf(
         "pcmu",
         "ulaw",
         "pcma",
         "alaw",
         "g722",
-        "gsm",
-        "sln",
+        "slin",
     )
 
     fun isVideo(extension: String): Boolean = extension.lowercase() in VIDEO_EXTENSIONS
diff --git a/shared/src/test/kotlin/dev/twango/jetplay/media/MediaClassificationTest.kt b/shared/src/test/kotlin/dev/twango/jetplay/media/MediaClassificationTest.kt
index c444757f..86daf4f2 100644
--- a/shared/src/test/kotlin/dev/twango/jetplay/media/MediaClassificationTest.kt
+++ b/shared/src/test/kotlin/dev/twango/jetplay/media/MediaClassificationTest.kt
@@ -64,11 +64,22 @@ class MediaClassificationTest {
 
     @Test
     fun transportStreamContainersClassifyAsVideo() {
-        assertTrue(MediaClassification.isVideo("mts"))
         assertTrue(MediaClassification.isVideo("m2ts"))
         assertTrue(MediaClassification.isVideo("m2t"))
     }
 
+    @Test
+    fun typeScriptExtensionsDoNotClassifyAsVideo() {
+        assertFalse(MediaClassification.isVideo("ts"))
+        assertFalse(MediaClassification.isVideo("mts"))
+    }
+
+    @Test
+    fun signedLinearUsesNonCollidingExtension() {
+        assertTrue(MediaClassification.rawAudioExtensions.contains("slin"))
+        assertFalse(MediaClassification.rawAudioExtensions.contains("sln"))
+    }
+
     @Test
     fun rawAudioExtensionsNeedTranscoding() {
         MediaClassification.rawAudioExtensions.forEach {