diff --git a/media/ffvpx/libavcodec/moz.build b/media/ffvpx/libavcodec/moz.build
index 738fe835d8..f3c7edb67c 100644
--- a/media/ffvpx/libavcodec/moz.build
+++ b/media/ffvpx/libavcodec/moz.build
@@ -157,13 +157,6 @@ SOURCES += [
     'xiph.c'
 ]
 
-if CONFIG['MOZ_LIBAV_FFT']:
-    SOURCES += [
-        'avfft.c',
-        'fft_float.c',
-        'rdft.c',
-    ]
-
 SYMBOLS_FILE = 'avcodec.symbols'
 NO_VISIBILITY_FLAGS = True
 
diff --git a/media/ffvpx/libavcodec/x86/moz.build b/media/ffvpx/libavcodec/x86/moz.build
index 9bafda725e..99b76894ac 100644
--- a/media/ffvpx/libavcodec/x86/moz.build
+++ b/media/ffvpx/libavcodec/x86/moz.build
@@ -75,12 +75,6 @@ SOURCES += [
     'vp9mc_16bpp.asm',
 ]
 
-if CONFIG['MOZ_LIBAV_FFT']:
-    SOURCES += [
-        'fft.asm',
-        'fft_init.c',
-    ]
-
 FINAL_LIBRARY = 'mozavcodec'
 
 include('/media/ffvpx/ffvpxcommon.mozbuild')