diff --git a/lib/core/agent.py b/lib/core/agent.py
index dd03186df..8f678af87 100644
--- a/lib/core/agent.py
+++ b/lib/core/agent.py
@@ -184,8 +184,11 @@ class Agent:
         @rtype: C{str}
         """
 
-        nulledCastedField = queries[kb.dbms].cast % field
-        nulledCastedField = queries[kb.dbms].isnull % nulledCastedField
+        if field.startswith("(CASE"):
+            nulledCastedField = field
+        else:
+            nulledCastedField = queries[kb.dbms].cast % field
+            nulledCastedField = queries[kb.dbms].isnull % nulledCastedField
 
         return nulledCastedField
 
diff --git a/lib/core/settings.py b/lib/core/settings.py
index 363c2a5a2..0b7841353 100644
--- a/lib/core/settings.py
+++ b/lib/core/settings.py
@@ -83,7 +83,8 @@ SQL_STATEMENTS    = {
                              " limit ",
                              " offset ",
                              " union all ",
-                             " rownum as ",    ),
+                             " rownum as ",
+                             "(case ",         ),
 
                       "SQL data definition":   (
                              "create ",