diff --git a/libavfilter/vf_convolve.c b/libavfilter/vf_convolve.c
index 024eb68486..90ec98715b 100644
--- a/libavfilter/vf_convolve.c
+++ b/libavfilter/vf_convolve.c
@@ -590,7 +590,9 @@ static av_cold void uninit(AVFilterContext *ctx)
 
         for (j = 0; j < MAX_THREADS; j++) {
             av_fft_end(s->fft[i][j]);
+            s->fft[i][j] = NULL;
             av_fft_end(s->ifft[i][j]);
+            s->ifft[i][j] = NULL;
         }
     }