diff --git a/.travis/build-coveralls.sh b/.travis/build-coveralls.sh
index a632961024..e250f80d3b 100755
--- a/.travis/build-coveralls.sh
+++ b/.travis/build-coveralls.sh
@@ -11,5 +11,10 @@ if ! travis_isPush; then
     exit 0
 fi
 
+#
+# for java9: enable all modules.
+# coveralls plugin seems to need java.xml.bind module
+#
+echo "MAVEN_OPTS='-Xms1g -Xmx1g --add-modules java.se.ee'" > $HOME/.mavenrc
 
 ./mvnw clean test jacoco:report coveralls:report -Pcoveralls -B -V
diff --git a/.travis/build-sonar.sh b/.travis/build-sonar.sh
index 0d2313efcb..5ded5bcb7f 100755
--- a/.travis/build-sonar.sh
+++ b/.travis/build-sonar.sh
@@ -11,6 +11,11 @@ if ! travis_isPush; then
     exit 0
 fi
 
+#
+# for java9: enable all modules.
+# sonar plugin seems to need java.xml.bind module
+#
+echo "MAVEN_OPTS='-Xms1g -Xmx1g --add-modules java.se.ee'" > $HOME/.mavenrc
 
 # Run the build, truncate output due to Travis log limits
 ./mvnw clean org.jacoco:jacoco-maven-plugin:prepare-agent package sonar:sonar -Dsonar.host.url=https://sonarqube.com -Dsonar.login=${SONAR_TOKEN} -B -V