diff --git a/packages/core-mt/package.json b/packages/core-mt/package.json
index c90dfcd..7ebdc54 100644
--- a/packages/core-mt/package.json
+++ b/packages/core-mt/package.json
@@ -28,7 +28,7 @@
     "transcode"
   ],
   "author": "Jerome Wu <jeromewus@gmail.com>",
-  "license": "MIT",
+  "license": "GPL-2.0-or-later",
   "bugs": {
     "url": "https://github.com/ffmpegwasm/ffmpeg.wasm/issues"
   },
diff --git a/packages/core/package.json b/packages/core/package.json
index b7fa24c..f4c1323 100644
--- a/packages/core/package.json
+++ b/packages/core/package.json
@@ -28,7 +28,7 @@
     "transcode"
   ],
   "author": "Jerome Wu <jeromewus@gmail.com>",
-  "license": "MIT",
+  "license": "GPL-2.0-or-later",
   "bugs": {
     "url": "https://github.com/ffmpegwasm/ffmpeg.wasm/issues"
   },