failsafe plugin error with suiteXml

hi,

i am using maven failsafe plugin to run the integration tests
however, i am getting following error when i am executing integration tests
along with cobertura

execute goal mvn-failsafe-plugin: (failsafe-integration-tests) project x:
suiteXmlFiles is configured, but there is no TestNG dependency
<http://stackoverflow.com/questions/26233462/execute-goal-mvn-failsafe-plugin-failsafe-integration-tests-project-x-suitex>

can some one please suggest what could be the error
i have added TestNG dependnecy at every possible location in pom file
still the issue

please please suggest

regards