diff --git a/src/ol/reproj.js b/src/ol/reproj.js
index 6606b079d3..bedaa3d148 100644
--- a/src/ol/reproj.js
+++ b/src/ol/reproj.js
@@ -398,6 +398,7 @@ export function render(
   if (opt_renderEdges) {
     context.save();
 
+    context.globalCompositeOperation = 'source-over';
     context.strokeStyle = 'black';
     context.lineWidth = 1;