diff --git a/drivers/video/fbdev/geode/lxfb_core.c b/drivers/video/fbdev/geode/lxfb_core.c
index 8130e9eee2b4..556d8b1a9e06 100644
--- a/drivers/video/fbdev/geode/lxfb_core.c
+++ b/drivers/video/fbdev/geode/lxfb_core.c
@@ -235,6 +235,9 @@ static void get_modedb(struct fb_videomode **modedb, unsigned int *size)
 
 static int lxfb_check_var(struct fb_var_screeninfo *var, struct fb_info *info)
 {
+	if (!var->pixclock)
+		return -EINVAL;
+
 	if (var->xres > 1920 || var->yres > 1440)
 		return -EINVAL;