X0306 4 2018-12-12 0 0001364962 IMPERVA INC IMPV 0001409173 BURNS MIKE C/O IMPERVA, INC. 3400 BRIDGE PARKWAY REDWOOD SHORES CA 94065 0 1 0 0 CFO and Treasurer Common Stock 2018-12-12 4 M 0 900 0.00 A 1429 D Common Stock 2018-12-12 4 F 0 312 55.54 D 1117 D Restricted Stock Units 2018-12-12 4 M 0 900 0.00 D 2028-01-01 Common Stock 900 47900 D On December 12, 2018, the Compensation Committee accelerated the vesting of 900 restricted stock units that were granted to Mr. Burns on January 2, 2018. Includes 529 shares of common stock acquired by the reporting person on November 15, 2018 under the Imperva, Inc. 2011 Employee Stock Purchase Plan. Exempt transaction pursuant to Rule 16b-3(e). The shares were automatically withheld by the Issuer in accordance with the agreement governing the RSUs to satisfy tax withholding obligations of the Reporting Person resulting from the vesting and settlement of the RSUs. The shares were withheld and cancelled by the Issuer and no shares were sold by the Reporting Person. Each restricted stock unit represents a contingent right to receive one share of common stock of the Issuer upon vesting. The restricted stock units vest as follows: 25% of the underlying shares vest one year following the vesting commencement date of February 15, 2018, with the remaining 75% vesting in equal quarterly installments over the next three years. The restricted stock units are subject to accelerated vesting in the event of a termination of employment under certain circumstances, including a termination following a change in control of the Issuer. The Issuer has up to 30 days following vesting to settle. The actual expiration date will be immediately following settlement. /s/ Shulamite White, Attorney-in-Fact 2018-12-14