diff --git a/drivers/video/fbdev/i740fb.c b/drivers/video/fbdev/i740fb.c
index 52cce0db8bd344a87d01ed0d9433916e955d9555..b595437a57528a54baab4f0dc311deee844aa128 100644
--- a/drivers/video/fbdev/i740fb.c
+++ b/drivers/video/fbdev/i740fb.c
@@ -657,6 +657,9 @@ static int i740fb_decode_var(const struct fb_var_screeninfo *var,
 
 static int i740fb_check_var(struct fb_var_screeninfo *var, struct fb_info *info)
 {
+	if (!var->pixclock)
+		return -EINVAL;
+
 	switch (var->bits_per_pixel) {
 	case 8:
 		var->red.offset	= var->green.offset = var->blue.offset = 0;