diff --git a/libavcodec/avcodec.h b/libavcodec/avcodec.h
index c7e1b648bfd86805fcd5b39544e6fe757c428e30..ec8228fee4de42d471d4374d992a0d60f535fd26 100644
--- a/libavcodec/avcodec.h
+++ b/libavcodec/avcodec.h
@@ -2444,7 +2444,7 @@ int avcodec_get_pix_fmt_loss(int dst_pix_fmt, int src_pix_fmt,
  * @param[out] loss_ptr Combination of flags informing you what kind of losses will occur.
  * @return The best pixel format to convert to or -1 if none was found.
  */
-int avcodec_find_best_pix_fmt(int pix_fmt_mask, int src_pix_fmt,
+int avcodec_find_best_pix_fmt(int64_t pix_fmt_mask, int src_pix_fmt,
                               int has_alpha, int *loss_ptr);
 
 
diff --git a/libavcodec/imgconvert.c b/libavcodec/imgconvert.c
index d182c5905d7193d5d9ac45423618447092b1f745..fcdfbd973b19dc107ea6837afeffb42ba9eb2dc2 100644
--- a/libavcodec/imgconvert.c
+++ b/libavcodec/imgconvert.c
@@ -772,7 +772,7 @@ static int avg_bits_per_pixel(int pix_fmt)
     return bits;
 }
 
-static int avcodec_find_best_pix_fmt1(int pix_fmt_mask,
+static int avcodec_find_best_pix_fmt1(int64_t pix_fmt_mask,
                                       int src_pix_fmt,
                                       int has_alpha,
                                       int loss_mask)
@@ -797,7 +797,7 @@ static int avcodec_find_best_pix_fmt1(int pix_fmt_mask,
     return dst_pix_fmt;
 }
 
-int avcodec_find_best_pix_fmt(int pix_fmt_mask, int src_pix_fmt,
+int avcodec_find_best_pix_fmt(int64_t pix_fmt_mask, int src_pix_fmt,
                               int has_alpha, int *loss_ptr)
 {
     int dst_pix_fmt, loss_mask, i;