diff --git a/libtiff/tif_strip.c b/libtiff/tif_strip.c
index 820a2544..afd7cb6e 100644
--- a/libtiff/tif_strip.c
+++ b/libtiff/tif_strip.c
@@ -287,7 +287,17 @@ uint64_t TIFFScanlineSize64(TIFF *tif)
         else
         {
             uint64_t scanline_samples;
-            scanline_samples = _TIFFMultiply64(tif, td->td_imagewidth,
+            uint32_t scanlinewidth = td->td_imagewidth;
+
+            if (td->td_photometric == PHOTOMETRIC_YCBCR)
+            {
+                uint16_t SubsamplingHor, SubsamplingVer;
+                TIFFGetFieldDefaulted(tif, TIFFTAG_YCBCRSUBSAMPLING, &SubsamplingHor, &SubsamplingVer);
+                if (SubsamplingHor > 1) // roundup width for YCbCr
+                    scanlinewidth = TIFFroundup_32(scanlinewidth, SubsamplingHor);
+	    }
+
+            scanline_samples = _TIFFMultiply64(tif, scanlinewidth,
                                                td->td_samplesperpixel, module);
             scanline_size =
                 TIFFhowmany_64(_TIFFMultiply64(tif, scanline_samples,