diff --git a/sonar-plugin-api/src/main/java/org/sonar/api/batch/bootstrap/ProjectDefinition.java b/sonar-plugin-api/src/main/java/org/sonar/api/batch/bootstrap/ProjectDefinition.java
index <HASH>..<HASH> 100644
--- a/sonar-plugin-api/src/main/java/org/sonar/api/batch/bootstrap/ProjectDefinition.java
+++ b/sonar-plugin-api/src/main/java/org/sonar/api/batch/bootstrap/ProjectDefinition.java
@@ -101,7 +101,7 @@ public final class ProjectDefinition implements BatchComponent {
    * @since 2.12
    */
   public ProjectDefinition setProperties(Properties properties) {
-    properties.putAll(properties);
+    this.properties.putAll(properties);
     return this;
   }
SONAR-<I> Fix ability to configure Maven plugins under Maven 2.x