No violation of the Leibniz rule. No fractional derivative

We demonstrate that a violation of the Leibniz rule is a characteristic property of derivatives of non-integer orders. We prove that all fractional derivatives D α , which satisfy the Leibniz rule D α ( fg ) = ( D α f ) g + f ( D α g ) , should have the integer order α = 1 , i.e. fractional derivatives of non-integer orders cannot satisfy the Leibniz rule.