X0306 4 2017-04-10 0 0001619739 Hess Midstream Partners LP HESM 0001552830 Global Infrastructure Investors II, LLC 12 EAST 49TH STREET, 38TH FLOOR NEW YORK NY 10017 1 0 1 0 0001552829 Global Infrastructure GP II, L.P. 12 EAST 49TH STREET, 38TH FLOOR NEW YORK NY 10017 1 0 1 0 0001702754 GIP Blue Holding GP, LLC 12 EAST 49TH STREET, 38TH FLOOR NEW YORK NY 10017 1 0 1 0 0001701926 GIP II Blue Holding Partnership, L.P. 12 EAST 49TH STREET, 38TH FLOOR NEW YORK NY 10017 1 0 1 0 Common Units 2017-04-10 4 J 0 1108500 D 5141327 I See footnote On April 10, 2017, the underwriters in the Issuer's initial public offering exercised their option to purchase additional common units. As a result, the Issuer did not issue 1,108,500 common units to GIP II Blue Holding Partnership, L.P. ("Blue Holding") which were previously reported as beneficially owned by the reporting persons. The securities reported herein are held by Blue Holding. Global Infrastructure Investors II, LLC ("Global Investors") is the sole general partner of Global Infrastructure GP II, L.P. ("Global GP"), which is the sole member of GIP Blue Holding GP, LLC, ("Blue Holding GP"), which is the general partner of Blue Holding. As such, each of Global Investors, Global GP and Blue Holding GP may be deemed to beneficially own the securities held of record by Blue Holding. Each such entity disclaims beneficial ownership of such securities except to the extent of their pecuniary interest therein. Global Infrastructure Investors II, LLC, By: /s/ Mark Levitt, Secretary 2017-04-12 Global Infrastructure GP II, L.P., By: Global Infrastructure Investors II, LLC, its general partner, By: /s/ Mark Levitt, Secretary 2017-04-12 GIP Blue Holding GP, LLC, By: /s/ Mark Levitt, Secretary 2017-04-12 GIP II Blue Holding Partnership, L.P., By: GIP Blue Holding GP, LLC, its general partner, By: /s/ Mark Levitt, Secretary 2017-04-12