diff --git a/external-sop/src/main/java/sop/external/operation/ListProfilesExternal.java b/external-sop/src/main/java/sop/external/operation/ListProfilesExternal.java
index 85eae6c..1c6cdf3 100644
--- a/external-sop/src/main/java/sop/external/operation/ListProfilesExternal.java
+++ b/external-sop/src/main/java/sop/external/operation/ListProfilesExternal.java
@@ -13,7 +13,7 @@ import java.util.Arrays;
 import java.util.List;
 import java.util.Properties;
 
-public class ListProfilesExternal extends ListProfiles {
+public class ListProfilesExternal implements ListProfiles {
 
     private final List<String> commandList = new ArrayList<>();
     private final List<String> envList;
diff --git a/sop-java/src/main/java/sop/exception/SOPGPException.java b/sop-java/src/main/java/sop/exception/SOPGPException.java
index a192c6c..04da74d 100644
--- a/sop-java/src/main/java/sop/exception/SOPGPException.java
+++ b/sop-java/src/main/java/sop/exception/SOPGPException.java
@@ -405,6 +405,10 @@ public abstract class SOPGPException extends RuntimeException {
             super();
         }
 
+        public UnsupportedProfile(String errorMessage) {
+            super(errorMessage);
+        }
+
         @Override
         public int getExitCode() {
             return EXIT_CODE;
diff --git a/sop-java/src/main/java/sop/operation/ListProfiles.java b/sop-java/src/main/java/sop/operation/ListProfiles.java
index bdfa811..e27789f 100644
--- a/sop-java/src/main/java/sop/operation/ListProfiles.java
+++ b/sop-java/src/main/java/sop/operation/ListProfiles.java
@@ -6,14 +6,10 @@ package sop.operation;
 
 import java.util.List;
 
-public abstract class ListProfiles {
+public interface ListProfiles {
 
-    public ListProfiles() {
+    List<String> ofCommand(String command);
 
-    }
-
-    public abstract List<String> ofCommand(String command);
-
-    public abstract List<String> global();
+    List<String> global();
 
 }