X0306 4 2015-12-14 0 0001273441 GRAN TIERRA ENERGY INC. GTE 0001642424 Guidry Gary C/O GRAN TIERRA ENERGY INC. 200, 150 13 AVENUE SW CALGARY A0 T2R 0V2 ALBERTA, CANADA 1 1 0 0 President and CEO Common Stock 2015-12-14 4 P 0 71376 1.998 A 2415500 D The price reported in Column 4 is a weighted average price. These shares were purchased in multiple transactions at prices ranging from $2.71 (CDN) to $2.75 (CDN), inclusive. The undersigned hereby undertakes to provide the Issuer, any security holder of the Issuer or the staff of the U.S. Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth herein. Purchase price of security was transacted in Canadian currency and converted to U.S. currency. 100,000 shares of common stock were previously incorrectly reported as being held indirectly by the Reporting Person. Beneficial ownership of these shares is held directly as opposed to indirectly and the Reporting Person's beneficial ownership has been modified to reflect this change. /s/ Gary Guidry 2015-12-15