diff --git a/libavcodec/pngdec.c b/libavcodec/pngdec.c
index 36db29e53e..5b02a4d28a 100644
--- a/libavcodec/pngdec.c
+++ b/libavcodec/pngdec.c
@@ -631,7 +631,7 @@ static int decode_frame(AVCodecContext *avctx,
                 } else if ((s->bits_per_pixel == 1 || s->bits_per_pixel == 2 || s->bits_per_pixel == 4 || s->bits_per_pixel == 8) &&
                            s->color_type == PNG_COLOR_TYPE_PALETTE) {
                     avctx->pix_fmt = AV_PIX_FMT_PAL8;
-                } else if (s->bit_depth == 1) {
+                } else if (s->bit_depth == 1 && s->bits_per_pixel == 1) {
                     avctx->pix_fmt = AV_PIX_FMT_MONOBLACK;
                 } else if (s->bit_depth == 8 &&
                            s->color_type == PNG_COLOR_TYPE_GRAY_ALPHA) {