diff --git a/model/src/main/java/lcsb/mapviewer/model/map/model/SubmodelConnection.java b/model/src/main/java/lcsb/mapviewer/model/map/model/SubmodelConnection.java
index d8b581c8c0409a529ae5a5b73241d95a8724ff21..d3fbc2027ff027de8c95169fd4c399baca2115ce 100644
--- a/model/src/main/java/lcsb/mapviewer/model/map/model/SubmodelConnection.java
+++ b/model/src/main/java/lcsb/mapviewer/model/map/model/SubmodelConnection.java
@@ -6,6 +6,8 @@ import javax.persistence.DiscriminatorColumn;
 import javax.persistence.DiscriminatorType;
 import javax.persistence.DiscriminatorValue;
 import javax.persistence.Entity;
+import javax.persistence.EnumType;
+import javax.persistence.Enumerated;
 import javax.persistence.FetchType;
 import javax.persistence.GeneratedValue;
 import javax.persistence.GenerationType;
@@ -63,6 +65,7 @@ public abstract class SubmodelConnection implements Serializable {
   /**
    * Type of the connection.
    */
+  @Enumerated(EnumType.STRING)
   private SubmodelType type;
 
   /**
diff --git a/persist/src/main/resources/db/migration/12.2.0~alpha.0/V12.2.0.20181024.5__submodel_type_changed_to_string.sql b/persist/src/main/resources/db/migration/12.2.0~alpha.0/V12.2.0.20181024.5__submodel_type_changed_to_string.sql
new file mode 100644
index 0000000000000000000000000000000000000000..e1de1b2d3369283088e84afad0713b75f56a562f
--- /dev/null
+++ b/persist/src/main/resources/db/migration/12.2.0~alpha.0/V12.2.0.20181024.5__submodel_type_changed_to_string.sql
@@ -0,0 +1,8 @@
+-- change in layout
+alter table submodel_connection_table add column type_string varchar(31);
+update submodel_connection_table set type_string='DOWNSTREAM_TARGETS' where type=0;
+update submodel_connection_table set type_string='PATHWAY' where type=1;
+update submodel_connection_table set type_string='UNKNOWN' where type=2;
+
+alter table submodel_connection_table drop column type;
+alter table submodel_connection_table rename column type_string to type;