diff --git a/src/input.js b/src/input.js
index 1b183a5f..9a6f4e0d 100644
--- a/src/input.js
+++ b/src/input.js
@@ -112,7 +112,11 @@ export function handlePaste(view, _, slice) {
 }
 
 export function handleMouseDown(view, startEvent) {
-  if (startEvent.ctrlKey || startEvent.metaKey) return
+  if (startEvent.ctrlKey || 
+      startEvent.metaKey || 
+      startEvent.which !== 1 /*not left click*/) {
+    return;
+  }
 
   let startDOMCell = domInCell(view, startEvent.target), $anchor
   if (startEvent.shiftKey && (view.state.selection instanceof CellSelection)) {