diff --git a/libavcodec/proresdec2.c b/libavcodec/proresdec2.c
index 932f85f73b..2d47a13030 100644
--- a/libavcodec/proresdec2.c
+++ b/libavcodec/proresdec2.c
@@ -180,7 +180,10 @@ static int decode_picture_header(AVCodecContext *avctx, const uint8_t *buf, cons
     else
         ctx->mb_height = (avctx->height + 15) >> 4;
 
-    slice_count = AV_RB16(buf + 5);
+    // QT ignores the written value
+    // slice_count = AV_RB16(buf + 5);
+    slice_count = ctx->mb_height * ((ctx->mb_width >> log2_slice_mb_width) +
+                                    av_popcount(ctx->mb_width & (1 << log2_slice_mb_width) - 1));
 
     if (ctx->slice_count != slice_count || !ctx->slices) {
         av_freep(&ctx->slices);
diff --git a/libavcodec/version.h b/libavcodec/version.h
index 71e0703b8e..02c2a089e6 100644
--- a/libavcodec/version.h
+++ b/libavcodec/version.h
@@ -30,7 +30,7 @@
 
 #define LIBAVCODEC_VERSION_MAJOR  57
 #define LIBAVCODEC_VERSION_MINOR  13
-#define LIBAVCODEC_VERSION_MICRO 101
+#define LIBAVCODEC_VERSION_MICRO 102
 
 #define LIBAVCODEC_VERSION_INT  AV_VERSION_INT(LIBAVCODEC_VERSION_MAJOR, \
                                                LIBAVCODEC_VERSION_MINOR, \