The present invention concerns a tension indicator (10) for a strap; the tension indicator comprising a first part (11) for receiving a length of the strap, a second part (12) movably mounted with respect to the first part between open and closed positions, the second part having strap engagement means (23) for engaging said length of strap. The strap engagement means is biassed relative to the first part for pulling any slack in the strap into the first part, thereby allowing the second part to move to said open position.