diff --git a/srcpkgs/thunderbird/template b/srcpkgs/thunderbird/template
index 397e3b246ae..9709c5339bc 100644
--- a/srcpkgs/thunderbird/template
+++ b/srcpkgs/thunderbird/template
@@ -72,6 +72,7 @@ post_patch() {
 	_clear_vendor_checksums audio_thread_priority
 	_clear_vendor_checksums num-traits
 	_clear_vendor_checksums glslopt
+	_clear_vendor_checksums mp4parse
 }
 
 do_build() {