diff --git a/qulice-spi/src/main/java/com/qulice/spi/ResourceValidator.java b/qulice-spi/src/main/java/com/qulice/spi/ResourceValidator.java
index d8c7f7111..f74d71f2d 100644
--- a/qulice-spi/src/main/java/com/qulice/spi/ResourceValidator.java
+++ b/qulice-spi/src/main/java/com/qulice/spi/ResourceValidator.java
@@ -17,7 +17,7 @@ public interface ResourceValidator {
     /**
      * Validate and throws exception if there are any problems.
      * @param files Files to validate
-     * @return Validation results
+     * @return Non-null collection of validation results. Returns an empty collection if no violations are found.
      */
     Collection<Violation> validate(Collection<File> files);