diff --git a/server/services/src/main/java/org/zanata/rest/editor/dto/ReviewData.java b/server/services/src/main/java/org/zanata/rest/editor/dto/ReviewData.java
index 6bc765a03d..f7fb925e1e 100644
--- a/server/services/src/main/java/org/zanata/rest/editor/dto/ReviewData.java
+++ b/server/services/src/main/java/org/zanata/rest/editor/dto/ReviewData.java
@@ -6,6 +6,7 @@
 import org.zanata.common.ContentState;
 
 import javax.validation.constraints.NotNull;
+import javax.validation.constraints.Size;
 import java.io.Serializable;
 
 /**
@@ -26,6 +27,7 @@ public class ReviewData implements Serializable {
     private Integer revision;
 
     @JsonProperty("comment")
+    @Size(max = 500)
     private String comment;
 
     private Long reviewCriteriaId;