diff --git a/minesweeper.js b/minesweeper.js
index dace0d2..a76e568 100644
--- a/minesweeper.js
+++ b/minesweeper.js
@@ -164,15 +164,35 @@ window.addEventListener("mousedown", event => {
     draw();
 });
 
+function columnContainsOnlyUnrevealed(column) {
+    return column.every(cell => !cell.isRevealed);
+}
+
 window.addEventListener("wheel", event => {
+    let deltaX = 0, deltaY = 0;
+
     if (event.shiftKey) {
-        scrollX += event.deltaY;
+        deltaX = event.deltaY;
     } else {
-        scrollX += event.deltaX;
-        scrollY += event.deltaY;
+        deltaX = event.deltaX;
+        deltaY = event.deltaY;
     }
 
-    // TODO create new rows/columns on scroll
+    console.log(scrollY + deltaY + window.innerHeight, board.length * CELL_SIZE);
+    if (scrollY + deltaY + window.innerHeight > board.length * CELL_SIZE) {
+        if (board.slice(-20).every(columnContainsOnlyUnrevealed)) {
+            console.log("ignoring");
+            return;
+        }
+
+        const diff = scrollY + window.innerHeight - board.length * CELL_SIZE;
+
+        for (let i = 0; i < diff + CELL_SIZE; i += CELL_SIZE)
+            createRowAtBottom();
+    }
+
+    scrollX += deltaX;
+    scrollY += deltaY;
 
     draw();
 });