diff --git a/libavcodec/ac3enc.c b/libavcodec/ac3enc.c
index 71bc8d0361..af70c12ed8 100644
--- a/libavcodec/ac3enc.c
+++ b/libavcodec/ac3enc.c
@@ -73,8 +73,6 @@ static int16_t xsin1[128];
 /* new exponents are sent if their Norm 1 exceed this number */
 #define EXP_DIFF_THRESHOLD 1000
 
-static void fft_init(int ln);
-
 static inline int16_t fix15(float a)
 {
     int v;