diff --git a/modules/ximgproc/src/thinning.cpp b/modules/ximgproc/src/thinning.cpp
index 0dcceb01410..b3a7dc15eb4 100644
--- a/modules/ximgproc/src/thinning.cpp
+++ b/modules/ximgproc/src/thinning.cpp
@@ -99,7 +99,7 @@ static void thinningIteration(Mat &img, Mat &marker, const uint8_t* const lut) {
     // Parallelized iteration over pixels excluding the boundary
     parallel_for_(Range(1, rows - 1), [&](const Range& range) {
         for (int i = range.start; i < range.end; i++) {
-            uchar* imgRow = img.ptr(i);
+            const uchar* imgRow = img.ptr(i);
             uchar* markerRow = marker.ptr(i);
             for (int j = 1; j < cols - 1; j++) {
                 if (imgRow[j]) {
@@ -119,7 +119,6 @@ static void thinningIteration(Mat &img, Mat &marker, const uint8_t* const lut) {
         }
     });
 
-    // Bitwise AND and reset marker for the next iteration
     img &= marker;
 }
 
@@ -132,7 +131,8 @@ void thinning(InputArray input, OutputArray output, int thinningType){
     Mat processed = input_ / 255;
     Mat prev = processed.clone();
 
-    Mat marker,marker_inner = processed(Rect(1, 1, processed.cols - 2, processed.rows - 2));
+    Mat marker;
+    Mat marker_inner = processed(Rect(1, 1, processed.cols - 2, processed.rows - 2));
     copyMakeBorder(marker_inner, marker, 1, 1, 1, 1, BORDER_ISOLATED | BORDER_CONSTANT, Scalar(255));
 
     const auto lutIter0 = (thinningType == THINNING_GUOHALL) ? lut_guo_iter0 : lut_zhang_iter0;