diff --git a/java-checks/src/main/java/org/sonar/java/checks/design/ClassCouplingCheck.java b/java-checks/src/main/java/org/sonar/java/checks/design/ClassCouplingCheck.java
index 1c541914b06..b515b0be6d5 100644
--- a/java-checks/src/main/java/org/sonar/java/checks/design/ClassCouplingCheck.java
+++ b/java-checks/src/main/java/org/sonar/java/checks/design/ClassCouplingCheck.java
@@ -63,7 +63,7 @@ public void visitClass(ClassTree tree) {
   }
 
   @Override
-  public void checkTypes(@Nullable Tree type, Set<String> types) {
+  public void checkTypes(@Nullable Tree type, @Nullable Set<String> types) {
     if (type == null || types == null) {
       return;
     }
diff --git a/java-checks/src/main/java/org/sonar/java/checks/design/ClassImportCouplingCheck.java b/java-checks/src/main/java/org/sonar/java/checks/design/ClassImportCouplingCheck.java
index 75f1c9f33ab..3bbb97e5c55 100644
--- a/java-checks/src/main/java/org/sonar/java/checks/design/ClassImportCouplingCheck.java
+++ b/java-checks/src/main/java/org/sonar/java/checks/design/ClassImportCouplingCheck.java
@@ -109,7 +109,7 @@ private List<JavaFileScannerContext.Location> getSecondaryLocations() {
   }
 
   @Override
-  public void checkTypes(@Nullable Tree type, Set<String> types) {
+  public void checkTypes(@Nullable Tree type, @Nullable Set<String> types) {
     if (type == null || types == null) {
       return;
     }