diff --git a/libaf/Makefile b/libaf/Makefile
index 6f7b4b5c0b..e923f258af 100644
--- a/libaf/Makefile
+++ b/libaf/Makefile
@@ -29,7 +29,6 @@ SRCS=af.c \
      window.c \
      $(AF_SRCS) \
 
-LIBAV_INC =
 ifeq ($(CONFIG_LIBAVUTIL),yes)
 LIBAV_INC += -I../libavutil
 endif
diff --git a/libmpcodecs/Makefile b/libmpcodecs/Makefile
index c016c85894..d91cefd95a 100644
--- a/libmpcodecs/Makefile
+++ b/libmpcodecs/Makefile
@@ -267,7 +267,6 @@ ifeq ($(CONFIG_MP3LAME),yes)
 ENCODER_SRCS += ae_lame.c
 endif
 
-LIBAV_INC =
 ifeq ($(CONFIG_LIBAVUTIL),yes)
 LIBAV_INC += -I../libavutil
 endif
diff --git a/libmpdemux/Makefile b/libmpdemux/Makefile
index 7af5118a00..5214e86bcf 100644
--- a/libmpdemux/Makefile
+++ b/libmpdemux/Makefile
@@ -79,7 +79,6 @@ MUXERS = muxer.c \
         muxer_rawaudio.c \
         muxer_rawvideo.c \
 
-LIBAV_INC =
 ifeq ($(CONFIG_LIBAVUTIL),yes)
 LIBAV_INC += -I../libavutil
 endif
diff --git a/libvo/Makefile b/libvo/Makefile
index 868c37da3e..8ac11519ab 100644
--- a/libvo/Makefile
+++ b/libvo/Makefile
@@ -15,7 +15,6 @@ SRCS=aclib.c \
      vo_yuv4mpeg.c \
      $(VO_SRCS) \
 
-LIBAV_INC =
 ifeq ($(CONFIG_LIBAVUTIL),yes)
 LIBAV_INC += -I../libavutil
 endif