diff --git a/libavformat/Makefile b/libavformat/Makefile
index fa325d2320..efe82f9f08 100644
--- a/libavformat/Makefile
+++ b/libavformat/Makefile
@@ -93,7 +93,7 @@ OBJS-$(CONFIG_AMRWB_DEMUXER)             += amr.o
 OBJS-$(CONFIG_ANM_DEMUXER)               += anm.o
 OBJS-$(CONFIG_APC_DEMUXER)               += apc.o
 OBJS-$(CONFIG_APE_DEMUXER)               += ape.o apetag.o img2.o
-OBJS-$(CONFIG_APM_DEMUXER)               += apm.o
+OBJS-$(CONFIG_APM_DEMUXER)               += apm.o riffdec.o
 OBJS-$(CONFIG_APNG_DEMUXER)              += apngdec.o
 OBJS-$(CONFIG_APNG_MUXER)                += apngenc.o
 OBJS-$(CONFIG_APTX_DEMUXER)              += aptxdec.o rawdec.o