diff --git a/src/main/java/de/ids_mannheim/korap/response/Notifications.java b/src/main/java/de/ids_mannheim/korap/response/Notifications.java
index 2f0e582..877c655 100644
--- a/src/main/java/de/ids_mannheim/korap/response/Notifications.java
+++ b/src/main/java/de/ids_mannheim/korap/response/Notifications.java
@@ -246,14 +246,6 @@
         return this;
     }
     
-    public Notifications addError (StatusCodes status, String msg, String ... terms) {
-        if (this.errors == null)
-            this.errors = new Messages();
-        this.errors.add(status.getCode(), msg, terms);
-        return this;
-    };
-
-
     /**
      * Appends a new error.
      * 
diff --git a/src/main/java/de/ids_mannheim/korap/util/StatusCodes.java b/src/main/java/de/ids_mannheim/korap/util/StatusCodes.java
index 9816669..bb97874 100644
--- a/src/main/java/de/ids_mannheim/korap/util/StatusCodes.java
+++ b/src/main/java/de/ids_mannheim/korap/util/StatusCodes.java
@@ -1,90 +1,81 @@
 package de.ids_mannheim.korap.util;
 
-public enum StatusCodes {
+public class StatusCodes {
     // 600 - 699 - Krill server error codes
-    UNABLE_TO_READ_INDEX(600), 
-    UNABLE_TO_FIND_INDEX(601),
-    UNABLE_TO_ADD_DOC_TO_INDEX(602),
-    UNABLE_TP_COMMIT_STAGED_DATA_TO_INDEX(603),
-    UNABLE_TO_CONNECT_TO_DB(604),
-    MISSING_REQUEST_PARAMETER(610),
-    ARBITRARY_DESERIALIZATION_ERROR(613),
-    UNABLE_TO_GENERATE_JSON(620),
-    UNABLE_TO_PARSE_JSON(621),
-    DOCUMENT_NOT_FOUND(630),
-    UNABLE_TO_EXTEND_CONTEXT(651),
-    SERVER_IS_RUNNING(680),
-    DOC_ADDED(681),
-    RESPONSE_TIME_EXCEEDED(682),
-    STAGED_DATA_COMMITTED(683),
-    
-//    700 - 799 - KoralQuery Deserialization errors
-    NO_QUERY_GIVEN(700),
-    MISSING_TYPE(701),
-    INVALID_BOUNDARY(702),
-    MISSING_OPERATION(703),
-    MISSING_OPERAND_LIST(704),
-    NUMBER_OF_OPERAND_NOT_ACCEPTABLE(705),
-    UNKNOWN_FRAME_TYPE(706),
-    INVALID_DISTANCE_CONSTRAINTS(707),
-    MISSING_DISTANCE(708),
-    VALID_CLASS_NUMBER_EXCEEDED(709),
-    MISSING_CLASS_ATTRIBUTE(710),
-    UNKNOWN_GROUP_OPERATION(711),
-    UNKNOWN_REFERENCE_OPERATION(712),
-    UNSUPPORTED_QUERY(713),
-    INVALID_SPAN_REFERENCE_PARAMETER(714),
-    UNSUPPORTED_ATTRIBUTE_TYPE(715),
-    UNKNOWN_RELATION(716),
-    MISSING_RELATION_NODE(717),
-    MISSING_RELATION_TERM(718),
-    INVALID_QUERY(719),
-    INVALID_MATCH_ID(730),
-    MISSING_KEY(740),
-    UNKNOWN_MATCH_RELATION(741),
-    MISSING_TERM_RELATION(743),
-    UNSUPPORTED_OPERAND(744),
-    UNSUPPORTED_TOKEN_TYPE(745),
-    UNSUPPORTED_TERM_TYPE(746),
-    NULL_ATTRIBUTE(747),
-    UNKNOWN_FLAG(748),
-    NON_WELL_FORMED_NOTIFICATION(750),
-    UNSUPPORTED_OPERATION(760),
-    UNSUPPORTED_OPERATOR(761),
-    QUERY_MATCH_EVERYWHERE(780),
-    IGNORE_OPTIONALITY(781),
-    IGNORE_EXCLUSIVITY(782),
-    QUERY_CANNOT_MATCH_ANYWHERE(783),
-    UNKNOWN_QUERY_SERIALIZATION_MESSAGE(799),
+    public static final int UNABLE_TO_READ_INDEX = 600;
+    public static final int UNABLE_TO_FIND_INDEX = 601;
+    public static final int UNABLE_TO_ADD_DOC_TO_INDEX = 602;
+    public static final int UNABLE_TP_COMMIT_STAGED_DATA_TO_INDEX = 603;
+    public static final int UNABLE_TO_CONNECT_TO_DB = 604;
+    public static final int MISSING_REQUEST_PARAMETER = 610;
+    public static final int ARBITRARY_DESERIALIZATION_ERROR = 613;
+    public static final int UNABLE_TO_GENERATE_JSON = 620;
+    public static final int UNABLE_TO_PARSE_JSON = 621;
+    public static final int DOCUMENT_NOT_FOUND = 630;
+    public static final int UNABLE_TO_EXTEND_CONTEXT = 651;
+    public static final int SERVER_IS_RUNNING = 680;
+    public static final int DOC_ADDED = 681;
+    public static final int RESPONSE_TIME_EXCEEDED = 682;
+    public static final int STAGED_DATA_COMMITTED = 683;
 
-//    800 - 899 - Virtual Collection Messages
-    MISSING_COLLECTION(800),
-    UNSUPPORTED_MATCH_TYPE(802),
-    UNKNOWN_VALUE_TYPE(804),
-    INVALID_VALUE(805),
-    INVALID_DATE_STRING(806),
-    INVALID_REGEX(807),
-    UNKNOWN_REWRITE_OPERATION(814),
-    MISSING_SOURCE(815),
-    MISSING_VALUE(820),
-    EMPTY_FILTER(830),
-    UNWRAPPABLE_FILTER(831),
-    INVALID_FILTER_OPERATION(832),
-    UNSUPPORTED_TYPE(843),
-    COLLECTIONS_UNSUPPORTED(850),
-    
-    
-//    900 - 999 - Corpus Data errors 
-    INVALID_OFFSET(952),
-    INCOMPLETE_OFFSET(953),
-    INVALID_FOUNDRY(970);
+    // 700 - 799 - KoralQuery Deserialization errors
+    public static final int NO_QUERY_GIVEN = 700;
+    public static final int MISSING_TYPE = 701;
+    public static final int INVALID_BOUNDARY = 702;
+    public static final int MISSING_OPERATION = 703;
+    public static final int MISSING_OPERAND_LIST = 704;
+    public static final int NUMBER_OF_OPERAND_NOT_ACCEPTABLE = 705;
+    public static final int UNKNOWN_FRAME_TYPE = 706;
+    public static final int INVALID_DISTANCE_CONSTRAINTS = 707;
+    public static final int MISSING_DISTANCE = 708;
+    public static final int VALID_CLASS_NUMBER_EXCEEDED = 709;
+    public static final int MISSING_CLASS_ATTRIBUTE = 710;
+    public static final int UNKNOWN_GROUP_OPERATION = 711;
+    public static final int UNKNOWN_REFERENCE_OPERATION = 712;
+    public static final int UNSUPPORTED_QUERY = 713;
+    public static final int INVALID_SPAN_REFERENCE_PARAMETER = 714;
+    public static final int UNSUPPORTED_ATTRIBUTE_TYPE = 715;
+    public static final int UNKNOWN_RELATION = 716;
+    public static final int MISSING_RELATION_NODE = 717;
+    public static final int MISSING_RELATION_TERM = 718;
+    public static final int INVALID_QUERY = 719;
+    public static final int INVALID_MATCH_ID = 730;
+    public static final int MISSING_KEY = 740;
+    public static final int UNKNOWN_MATCH_RELATION = 741;
+    public static final int MISSING_TERM_RELATION = 743;
+    public static final int UNSUPPORTED_OPERAND = 744;
+    public static final int UNSUPPORTED_TOKEN_TYPE = 745;
+    public static final int UNSUPPORTED_TERM_TYPE = 746;
+    public static final int NULL_ATTRIBUTE = 747;
+    public static final int UNKNOWN_FLAG = 748;
+    public static final int NON_WELL_FORMED_NOTIFICATION = 750;
+    public static final int UNSUPPORTED_OPERATION = 760;
+    public static final int UNSUPPORTED_OPERATOR = 761;
+    public static final int QUERY_MATCH_EVERYWHERE = 780;
+    public static final int IGNORE_OPTIONALITY = 781;
+    public static final int IGNORE_EXCLUSIVITY = 782;
+    public static final int QUERY_CANNOT_MATCH_ANYWHERE = 783;
+    public static final int UNKNOWN_QUERY_SERIALIZATION_MESSAGE = 799;
 
-    private int code;
-    StatusCodes (int code) {
-        this.code = code;
-    }
-   
-    public int getCode () {
-        return code;
-    }
+    // 800 - 899 - Virtual Collection Messages
+    public static final int MISSING_COLLECTION = 800;
+    public static final int UNSUPPORTED_MATCH_TYPE = 802;
+    public static final int UNKNOWN_VALUE_TYPE = 804;
+    public static final int INVALID_VALUE = 805;
+    public static final int INVALID_DATE_STRING = 806;
+    public static final int INVALID_REGEX = 807;
+    public static final int UNKNOWN_REWRITE_OPERATION = 814;
+    public static final int MISSING_SOURCE = 815;
+    public static final int MISSING_VALUE = 820;
+    public static final int EMPTY_FILTER = 830;
+    public static final int UNWRAPPABLE_FILTER = 831;
+    public static final int INVALID_FILTER_OPERATION = 832;
+    public static final int UNSUPPORTED_TYPE = 843;
+    public static final int COLLECTIONS_UNSUPPORTED = 850;
+
+    // 900 - 999 - Corpus Data errors 
+    public static final int INVALID_OFFSET = 952;
+    public static final int INCOMPLETE_OFFSET = 953;
+    public static final int INVALID_FOUNDRY = 970;
+
 }
diff --git a/src/test/java/de/ids_mannheim/korap/collection/TestKrillCollectionIndex.java b/src/test/java/de/ids_mannheim/korap/collection/TestKrillCollectionIndex.java
index 0446ee0..2a81fc0 100644
--- a/src/test/java/de/ids_mannheim/korap/collection/TestKrillCollectionIndex.java
+++ b/src/test/java/de/ids_mannheim/korap/collection/TestKrillCollectionIndex.java
@@ -9,7 +9,7 @@
 import de.ids_mannheim.korap.index.TextAnalyzer;
 import de.ids_mannheim.korap.response.Result;
 import de.ids_mannheim.korap.response.SearchContext;
-
+import de.ids_mannheim.korap.util.StatusCodes;
 import de.ids_mannheim.korap.Krill;
 import de.ids_mannheim.korap.query.QueryBuilder;
 
@@ -56,7 +56,9 @@
         assertEquals(0, tokens);
         assertEquals(0, sentences);
         assertEquals(0, paragraphs);
-
+        
+        assertEquals(1, kc.getErrors().size());
+        assertEquals(StatusCodes.UNABLE_TO_PARSE_JSON, kc.getErrors().get(0).getCode());
     }