diff --git a/libavcodec/wmavoice.c b/libavcodec/wmavoice.c
index f6561d7035..0cf10da8c4 100644
--- a/libavcodec/wmavoice.c
+++ b/libavcodec/wmavoice.c
@@ -515,7 +515,7 @@ static int kalman_smoothen(WMAVoiceContext *s, int pitch,
     float optimal_gain = 0, dot;
     const float *ptr = &in[-FFMAX(s->min_pitch_val, pitch - 3)],
                 *end = &in[-FFMIN(s->max_pitch_val, pitch + 3)],
-                *best_hist_ptr;
+                *best_hist_ptr = NULL;
 
     /* find best fitting point in history */
     do {