diff --git a/gst-libs/ext/Makefile.am b/gst-libs/ext/Makefile.am
index 2e709bec44..d25e019c58 100644
--- a/gst-libs/ext/Makefile.am
+++ b/gst-libs/ext/Makefile.am
@@ -1 +1 @@
-SUBDIRS = ffmpeg
+SUBDIRS = ffmpeg mplex