diff --git a/libavcodec/qcelpdec.c b/libavcodec/qcelpdec.c
index 1889f21055..32e74a6a7d 100644
--- a/libavcodec/qcelpdec.c
+++ b/libavcodec/qcelpdec.c
@@ -586,7 +586,7 @@ static void apply_pitch_filters(QCELPContext *q, float *cdn_vector)
  *
  * TIA/EIA/IS-733 2.4.3.3.5
  */
-void lspf2lpc(const float *lspf, float *lpc)
+static void lspf2lpc(const float *lspf, float *lpc)
 {
     double lsf[10];
     double bandwith_expansion_coeff = QCELP_BANDWITH_EXPANSION_COEFF;