diff --git a/libavdevice/fbdev.c b/libavdevice/fbdev.c
index 1156fb50a6..7edf10b9f6 100644
--- a/libavdevice/fbdev.c
+++ b/libavdevice/fbdev.c
@@ -231,7 +231,7 @@ static av_cold int fbdev_read_close(AVFormatContext *avctx)
 {
     FBDevContext *fbdev = avctx->priv_data;
 
-    munmap(fbdev->data, fbdev->frame_size);
+    munmap(fbdev->data, fbdev->fixinfo.smem_len);
     close(fbdev->fd);
 
     return 0;