diff --git a/libavcodec/fft-test.c b/libavcodec/fft-test.c
index 1c88a53fdd..6b3880cf5d 100644
--- a/libavcodec/fft-test.c
+++ b/libavcodec/fft-test.c
@@ -145,7 +145,7 @@ static void mdct_ref(FFTSample *output, FFTSample *input, int nbits)
 }
 
 #if CONFIG_FFT_FLOAT
-static void idct_ref(float *output, float *input, int nbits)
+static void idct_ref(FFTSample *output, FFTSample *input, int nbits)
 {
     int n = 1<<nbits;
     int k, i;
@@ -161,7 +161,7 @@ static void idct_ref(float *output, float *input, int nbits)
         output[i] = 2 * s / n;
     }
 }
-static void dct_ref(float *output, float *input, int nbits)
+static void dct_ref(FFTSample *output, FFTSample *input, int nbits)
 {
     int n = 1<<nbits;
     int k, i;
@@ -401,11 +401,11 @@ int main(int argc, char **argv)
         break;
     case TRANSFORM_DCT:
         memcpy(tab, tab1, fft_size * sizeof(FFTComplex));
-        d->dct_calc(d, tab);
+        d->dct_calc(d, (FFTSample *)tab);
         if (do_inverse) {
-            idct_ref(tab_ref, tab1, fft_nbits);
+            idct_ref((FFTSample*)tab_ref, (FFTSample *)tab1, fft_nbits);
         } else {
-            dct_ref(tab_ref, tab1, fft_nbits);
+            dct_ref((FFTSample*)tab_ref, (FFTSample *)tab1, fft_nbits);
         }
         err = check_diff((float *)tab_ref, (float *)tab, fft_size, 1.0);
         break;