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  <xsd:element id="qlys_StockIssuedDuringPeriodSharesRestrictedStockAwardVested" name="StockIssuedDuringPeriodSharesRestrictedStockAwardVested" nillable="true" substitutionGroup="xbrli:item" type="xbrli:sharesItemType" xbrli:periodType="duration" />
  <xsd:element id="qlys_StockIssuedDuringPeriodValueRestrictedStockAwardVested" name="StockIssuedDuringPeriodValueRestrictedStockAwardVested" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element id="qlys_TaxCutsandJobsActof2017IncompleteAccountingProvisionalIncomeTaxExpenseBenefit" name="TaxCutsandJobsActof2017IncompleteAccountingProvisionalIncomeTaxExpenseBenefit" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element id="qlys_TaxCutsandJobsActof2017IncompleteAccountingTransitionTaxforAccumulatedForeignEarningsProvisionalIncomeTaxExpenseBenefit" name="TaxCutsandJobsActof2017IncompleteAccountingTransitionTaxforAccumulatedForeignEarningsProvisionalIncomeTaxExpenseBenefit" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="duration" />
</xsd:schema>
