diff --git a/src/write.c b/src/write.c
index d755d56..8b53777 100644
--- a/src/write.c
+++ b/src/write.c
@@ -353,6 +353,7 @@
     avifRWStreamWriteChars(&s, "avif", 4);                                 // unsigned int(32) compatible_brands[];
     if (encoder->data->frames.count > 1) {                                 //
         avifRWStreamWriteChars(&s, "avis", 4);                             // ... compatible_brands[]
+        avifRWStreamWriteChars(&s, "msf1", 4);                             // ... compatible_brands[]
     }                                                                      //
     avifRWStreamWriteChars(&s, "mif1", 4);                                 // ... compatible_brands[]
     avifRWStreamWriteChars(&s, "miaf", 4);                                 // ... compatible_brands[]