diff --git a/libswscale/swscale_unscaled.c b/libswscale/swscale_unscaled.c
index c5c36e417f..99148d1385 100644
--- a/libswscale/swscale_unscaled.c
+++ b/libswscale/swscale_unscaled.c
@@ -1284,7 +1284,7 @@ static int rgbToRgbWrapper(SwsContext *c, const uint8_t *src[], int srcStride[],
         if (dstStride[0] * srcBpp == srcStride[0] * dstBpp && srcStride[0] > 0 &&
             !(srcStride[0] % srcBpp) && !dst_bswap && !src_bswap)
             conv(srcPtr, dstPtr + dstStride[0] * srcSliceY,
-                 srcSliceH * srcStride[0]);
+                 (srcSliceH - 1) * srcStride[0] + c->srcW * srcBpp);
         else {
             int i, j;
             dstPtr += dstStride[0] * srcSliceY;