diff --git a/gradoop-flink/src/main/java/org/gradoop/flink/io/impl/json/JSONDataSink.java b/gradoop-flink/src/main/java/org/gradoop/flink/io/impl/json/JSONDataSink.java
index 26856f543019..aabd19f626d8 100644
--- a/gradoop-flink/src/main/java/org/gradoop/flink/io/impl/json/JSONDataSink.java
+++ b/gradoop-flink/src/main/java/org/gradoop/flink/io/impl/json/JSONDataSink.java
@@ -30,7 +30,11 @@
  * Write an EPGM representation into three separate JSON files. The format
  * is documented at {@link GraphHeadToJSON}, {@link VertexToJSON} and
  * {@link EdgeToJSON}.
+ *
+ * @deprecated This class is deprecated. For example use
+ * {@link org.gradoop.flink.io.impl.csv.CSVDataSink}
  */
+@Deprecated
 public class JSONDataSink extends JSONBase implements DataSink {
 
   /**
diff --git a/gradoop-flink/src/main/java/org/gradoop/flink/io/impl/json/JSONDataSource.java b/gradoop-flink/src/main/java/org/gradoop/flink/io/impl/json/JSONDataSource.java
index 5bf745cd4806..bee1be2b60c4 100644
--- a/gradoop-flink/src/main/java/org/gradoop/flink/io/impl/json/JSONDataSource.java
+++ b/gradoop-flink/src/main/java/org/gradoop/flink/io/impl/json/JSONDataSource.java
@@ -34,7 +34,11 @@
 /**
  * Creates an EPGM instance from JSON files. The exact format is documented in
  * {@link JSONToGraphHead}, {@link JSONToVertex}, {@link JSONToEdge}.
+ *
+ * @deprecated This class is deprecated. For example use
+ * {@link org.gradoop.flink.io.impl.csv.CSVDataSource}
  */
+@Deprecated
 public class JSONDataSource extends JSONBase implements DataSource {
 
   /**