diff --git a/libswscale/swscale_unscaled.c b/libswscale/swscale_unscaled.c
index c0161c24e9..c7e6a28ac5 100644
--- a/libswscale/swscale_unscaled.c
+++ b/libswscale/swscale_unscaled.c
@@ -806,7 +806,7 @@ static int check_image_pointers(uint8_t *data[4], enum PixelFormat pix_fmt,
  * swscale wrapper, so we don't need to export the SwsContext.
  * Assumes planar YUV to be in YUV order instead of YVU.
  */
-int sws_scale(struct SwsContext *c, const uint8_t* const srcSlice[],
+int attribute_align_arg sws_scale(struct SwsContext *c, const uint8_t* const srcSlice[],
               const int srcStride[], int srcSliceY, int srcSliceH,
               uint8_t* const dst[], const int dstStride[])
 {