diff --git a/src/db_postgres.nim b/src/db_postgres.nim
index 116356489f..6ea2bdbee3 100644
--- a/src/db_postgres.nim
+++ b/src/db_postgres.nim
@@ -16,14 +16,14 @@ type
   TDbConn* = PPGconn   ## encapsulates a database connection
   TRow* = seq[string]  ## a row of a dataset. NULL database values will be
                        ## transformed always to the empty string.
-  EDb* = object of EIO ## exception that is raised if a database error occurs
+  EDb* = object of IOError ## exception that is raised if a database error occurs
   
   TSqlQuery* = distinct string ## an SQL query string
 
-  FDb* = object of FIO ## effect that denotes a database operation
-  FReadDb* = object of FDB   ## effect that denotes a read operation
-  FWriteDb* = object of FDB  ## effect that denotes a write operation
-  
+  FDb* = object of IOEffect ## effect that denotes a database operation
+  FReadDb* = object of FDb   ## effect that denotes a read operation
+  FWriteDb* = object of FDb  ## effect that denotes a write operation
+
 proc sql*(query: string): TSqlQuery {.noSideEffect, inline.} =  
   ## constructs a TSqlQuery from the string `query`. This is supposed to be 
   ## used as a raw-string-literal modifier: