diff --git a/src/main/java/org/gcube/gcat/persistence/ckan/CKANGroup.java b/src/main/java/org/gcube/gcat/persistence/ckan/CKANGroup.java
index 1958d83..3cb6573 100644
--- a/src/main/java/org/gcube/gcat/persistence/ckan/CKANGroup.java
+++ b/src/main/java/org/gcube/gcat/persistence/ckan/CKANGroup.java
@@ -48,7 +48,7 @@ public class CKANGroup extends CKAN {
 		if(groupName == null)
 			return null;
 		
-		String regexGroupNameTransform = "[^A-Za-z0-9-_]";
+		String regexGroupNameTransform = "[^A-Za-z0-9-]";
 		String modified = groupName.trim().replaceAll(regexGroupNameTransform, "-").replaceAll("-+", "-").toLowerCase();
 		
 		if(modified.startsWith("-"))