diff --git a/jOOQ-test/src/org/jooq/test/_/testcases/PredicateTests.java b/jOOQ-test/src/org/jooq/test/_/testcases/PredicateTests.java
index e9bdb514de..8778dae2bb 100644
--- a/jOOQ-test/src/org/jooq/test/_/testcases/PredicateTests.java
+++ b/jOOQ-test/src/org/jooq/test/_/testcases/PredicateTests.java
@@ -304,6 +304,7 @@ extends BaseTest<A, AP, B, S, B2S, BS, L, X, DATE, BOOL, D, T, U, I, IPK, T658,
             case ASE:
             case DB2:
             case DERBY:
+            case FIREBIRD:
             case INGRES:
             case SQLITE:
             case SQLSERVER:
diff --git a/jOOQ/src/main/java/org/jooq/util/firebird/FirebirdDataType.java b/jOOQ/src/main/java/org/jooq/util/firebird/FirebirdDataType.java
index 647a8f459a..ad2da751e6 100644
--- a/jOOQ/src/main/java/org/jooq/util/firebird/FirebirdDataType.java
+++ b/jOOQ/src/main/java/org/jooq/util/firebird/FirebirdDataType.java
@@ -74,8 +74,8 @@ public class FirebirdDataType<T> extends AbstractDataType<T> {
     public static final FirebirdDataType<Boolean>     BOOLEAN               = new FirebirdDataType<Boolean>(SQLDataType.BOOLEAN, "boolean");
     public static final FirebirdDataType<BigDecimal>  DECIMAL               = new FirebirdDataType<BigDecimal>(SQLDataType.DECIMAL, "decimal");
     public static final FirebirdDataType<BigDecimal>  NUMERIC               = new FirebirdDataType<BigDecimal>(SQLDataType.NUMERIC, "numeric");
-    public static final FirebirdDataType<String>      VARCHAR               = new FirebirdDataType<String>(SQLDataType.VARCHAR, "varchar", "varchar(500)");
-    public static final FirebirdDataType<String>      CHARACTERVARYING      = new FirebirdDataType<String>(SQLDataType.VARCHAR, "character varying", "varchar(500)");
+    public static final FirebirdDataType<String>      VARCHAR               = new FirebirdDataType<String>(SQLDataType.VARCHAR, "varchar", "varchar(4000)");
+    public static final FirebirdDataType<String>      CHARACTERVARYING      = new FirebirdDataType<String>(SQLDataType.VARCHAR, "character varying", "varchar(4000)");
     public static final FirebirdDataType<String>      CHAR                  = new FirebirdDataType<String>(SQLDataType.CHAR, "char");
     public static final FirebirdDataType<String>      CHARACTER             = new FirebirdDataType<String>(SQLDataType.CHAR, "character");
     public static final FirebirdDataType<String>      CLOB                  = new FirebirdDataType<String>(SQLDataType.CLOB, "blob sub_type text");
@@ -99,10 +99,10 @@ public class FirebirdDataType<T> extends AbstractDataType<T> {
     protected static final FirebirdDataType<Double>  __FLOAT                = new FirebirdDataType<Double>(SQLDataType.FLOAT, "double precision");
     protected static final FirebirdDataType<String>  __LONGNVARCHAR         = new FirebirdDataType<String>(SQLDataType.LONGNVARCHAR, "blob sub_type text");
     protected static final FirebirdDataType<byte[]>  __LONGVARBINARY        = new FirebirdDataType<byte[]>(SQLDataType.LONGVARBINARY, "blob");
-    protected static final FirebirdDataType<String>  __LONGVARCHAR          = new FirebirdDataType<String>(SQLDataType.LONGVARCHAR, "varchar", "varchar(500)");
+    protected static final FirebirdDataType<String>  __LONGVARCHAR          = new FirebirdDataType<String>(SQLDataType.LONGVARCHAR, "varchar", "varchar(4000)");
     protected static final FirebirdDataType<String>  __NCHAR                = new FirebirdDataType<String>(SQLDataType.NCHAR, "char");
     protected static final FirebirdDataType<String>  __NCLOB                = new FirebirdDataType<String>(SQLDataType.NCLOB, "clob");
-    protected static final FirebirdDataType<String>  __NVARCHAR             = new FirebirdDataType<String>(SQLDataType.NVARCHAR, "varchar", "varchar(500)");
+    protected static final FirebirdDataType<String>  __NVARCHAR             = new FirebirdDataType<String>(SQLDataType.NVARCHAR, "varchar", "varchar(4000)");
     protected static final FirebirdDataType<Byte>    __TINYINT              = new FirebirdDataType<Byte>(SQLDataType.TINYINT, "smallint");
     protected static final FirebirdDataType<byte[]>  __VARBINARY            = new FirebirdDataType<byte[]>(SQLDataType.VARBINARY, "blob");