diff --git a/modules/ximgproc/src/edge_drawing.cpp b/modules/ximgproc/src/edge_drawing.cpp
index 655055e7a20..594ac23a154 100644
--- a/modules/ximgproc/src/edge_drawing.cpp
+++ b/modules/ximgproc/src/edge_drawing.cpp
@@ -5955,6 +5955,7 @@ void EdgeDrawingImpl::MyRGB2LabFast()
 
 void EdgeDrawingImpl::ComputeGradientMapByDiZenzo()
 {
+    memset(gradImg, 0, sizeof(ushort) * width * height);
     int max = 0;
 
     for (int i = 1; i < height - 1; i++) {