diff --git a/tools/gen_sonar_project_properties.py b/tools/gen_sonar_project_properties.py
index 2ef679f..832b7f1 100755
--- a/tools/gen_sonar_project_properties.py
+++ b/tools/gen_sonar_project_properties.py
@@ -69,6 +69,7 @@
 sonar.sources=%s
 sonar.tests=%s
 sonar.sourceEncoding=UTF-8
+sonar.java.source=1.7
 sonar.java.binaries=%s
 
 sonar.junit.reportsPath=%s