diff --git a/modules/videoio/src/cap_ffmpeg_impl.hpp b/modules/videoio/src/cap_ffmpeg_impl.hpp
index 48c9aa7a76a9d0aff3e2e4627ee9a82a63c1250b..eb7a23137ba65677759d2ee13614cb23d4a9e098 100644
--- a/modules/videoio/src/cap_ffmpeg_impl.hpp
+++ b/modules/videoio/src/cap_ffmpeg_impl.hpp
@@ -1707,7 +1707,7 @@ bool CvVideoWriter_FFMPEG::writeFrame( const unsigned char* data, int step, int
     const int CV_STEP_ALIGNMENT = 32;
     const size_t CV_SIMD_SIZE = 32;
     const size_t CV_PAGE_MASK = ~(4096 - 1);
-    const uchar* dataend = data + ((size_t)height * step);
+    const unsigned char* dataend = data + ((size_t)height * step);
     if (step % CV_STEP_ALIGNMENT != 0 ||
         (((size_t)dataend - CV_SIMD_SIZE) & CV_PAGE_MASK) != (((size_t)dataend + CV_SIMD_SIZE) & CV_PAGE_MASK))
     {