diff --git a/main.c b/main.c
index e39b4bd..1d2ba6a 100644
--- a/main.c
+++ b/main.c
@@ -18,6 +18,40 @@
 
 #define PX(x) ((x) << 3)
 
+typedef struct {
+	bool cells[GRID_SIZE][GRID_SIZE];
+} maze_t;
+
+static void draw_maze(Display *dpy, Window w, GC gc, const maze_t *m)
+{
+	// Draw walls
+	XFillRectangle(
+	    dpy, w, gc, PX(MARGIN), PX(MARGIN), PX(GRID_SIZE + 2),
+	    PX(WALL_THICKNESS));
+	XFillRectangle(
+	    dpy, w, gc, PX(MARGIN), PX(MARGIN + WALL_THICKNESS + GRID_SIZE),
+	    PX(GRID_SIZE + 2), PX(WALL_THICKNESS));
+	XFillRectangle(
+	    dpy, w, gc, PX(MARGIN), PX(MARGIN + WALL_THICKNESS + 1),
+	    PX(WALL_THICKNESS), PX(GRID_SIZE - 1));
+	XFillRectangle(
+	    dpy, w, gc, PX(MARGIN + WALL_THICKNESS + GRID_SIZE),
+	    PX(MARGIN + WALL_THICKNESS), PX(WALL_THICKNESS), PX(GRID_SIZE));
+
+	// Draw cells
+	for (int x = 0; x < GRID_SIZE; ++x) {
+		for (int y = 0; y < GRID_SIZE; ++y) {
+			if (m->cells[x][y])
+				continue;
+			const int left = PX(MARGIN + WALL_THICKNESS + x);
+			const int top = PX(MARGIN + WALL_THICKNESS + y);
+			XFillRectangle(dpy, w, gc, left, top, PX(1), PX(1));
+		}
+	}
+
+	XFlush(dpy);
+}
+
 int main(void)
 {
 	XEvent evt;
@@ -42,6 +76,10 @@ int main(void)
 		XNextEvent(dpy, &evt);
 	while (MapNotify != evt.type);
 
+	maze_t m;
+	memset(&m, 0, sizeof(maze_t));
+	draw_maze(dpy, w, gc, &m);
+
 	// Wait for window exit
 	bool is_del = false;
 	do {