diff --git a/libavformat/Makefile b/libavformat/Makefile
index ae168b6ff4bfe18e9204d37336bdc205d05c2a9d..53cc6753248f01654971426111f027ec5e9ff9c5 100644
--- a/libavformat/Makefile
+++ b/libavformat/Makefile
@@ -292,7 +292,7 @@ OBJS-$(CONFIG_SIFF_DEMUXER)              += siff.o
 OBJS-$(CONFIG_SMACKER_DEMUXER)           += smacker.o
 OBJS-$(CONFIG_SMJPEG_DEMUXER)            += smjpegdec.o smjpeg.o
 OBJS-$(CONFIG_SMJPEG_MUXER)              += smjpegenc.o smjpeg.o
-OBJS-$(CONFIG_SMOOTHSTREAMING_MUXER)     += smoothstreamingenc.o
+OBJS-$(CONFIG_SMOOTHSTREAMING_MUXER)     += smoothstreamingenc.o isom.o
 OBJS-$(CONFIG_SOL_DEMUXER)               += sol.o pcm.o
 OBJS-$(CONFIG_SOX_DEMUXER)               += soxdec.o pcm.o
 OBJS-$(CONFIG_SOX_MUXER)                 += soxenc.o
diff --git a/libavformat/smoothstreamingenc.c b/libavformat/smoothstreamingenc.c
index 5ddba7eb067a4934186ac70dfbe7944c730319b9..08e6526533e773ced3995f7fd375f7767c093457 100644
--- a/libavformat/smoothstreamingenc.c
+++ b/libavformat/smoothstreamingenc.c
@@ -30,6 +30,7 @@
 #include "os_support.h"
 #include "avc.h"
 #include "url.h"
+#include "isom.h"
 
 #include "libavutil/opt.h"
 #include "libavutil/avstring.h"
@@ -617,5 +618,6 @@ AVOutputFormat ff_smoothstreaming_muxer = {
     .write_header   = ism_write_header,
     .write_packet   = ism_write_packet,
     .write_trailer  = ism_write_trailer,
+    .codec_tag      = (const AVCodecTag* const []){ ff_mp4_obj_type, 0 },
     .priv_class     = &ism_class,
 };