

	For the three months ended June 30					For the six months ended June 30
(in millions of Canadian dollars)	2019			2018		2019		2018
Current income tax expense	$	142		$	85	$	243	$	166
Deferred income tax (recovery) expense	(18		)	37		20		78
Income tax expense	$	124		$	122	$	263	$	244

During the three months ended June 30, 2019, legislation was enacted to decrease the Alberta provincial corporate income tax rate. As a result of this change, the Company recorded a deferred tax recovery of $88 million in the second quarter of 2019 related to the revaluation of its deferred income tax balances as at January 1, 2019.

During the three months ended June 30, 2018, legislation was enacted to decrease the Iowa and Missouri state corporate income tax rates. As a result of these changes, the Company recorded a deferred tax recovery of $21 million in the second quarter of 2018 related to the revaluation of deferred income tax balances as at January 1, 2018.

The effective tax rates for the three and six months ended June 30, 2019 were 14.63% and 18.50%, respectively, compared to 21.88% and 23.73%, respectively for the same periods in 2018.

For the three months ended June 30, 2019, the effective tax rate excluding the discrete items of the foreign exchange ("FX") gain of $37 million on debt and lease liabilities and the $88 million deferred tax recovery on the Alberta provincial corporate income tax rate change, was 25.75%.

For the three months ended June 30, 2018, the effective tax rate excluding the discrete items of the FX loss of $44 million on debt and the $21 million deferred tax recovery on the Iowa and Missouri state corporate income tax rate changes, was 24.75%.

For the six months ended June 30, 2019, the effective tax rate excluding the discrete items of the FX gain of $82 million on debt and lease liabilities and the $88 million deferred tax recovery on the Alberta provincial corporate income tax rate change, was 25.75%.