diff --git a/jOOQ-meta/src/main/java/org/jooq/util/firebird/FirebirdTableDefinition.java b/jOOQ-meta/src/main/java/org/jooq/util/firebird/FirebirdTableDefinition.java
index e5415e2092..c8c9cbf9bc 100644
--- a/jOOQ-meta/src/main/java/org/jooq/util/firebird/FirebirdTableDefinition.java
+++ b/jOOQ-meta/src/main/java/org/jooq/util/firebird/FirebirdTableDefinition.java
@@ -49,6 +49,7 @@ import java.util.ArrayList;
 import java.util.List;
 
 import org.jooq.Record;
+import org.jooq.impl.DSL;
 import org.jooq.util.AbstractTableDefinition;
 import org.jooq.util.ColumnDefinition;
 import org.jooq.util.DefaultColumnDefinition;
@@ -79,7 +80,7 @@ public class FirebirdTableDefinition extends AbstractTableDefinition {
                 r.RDB$FIELD_NAME.trim(),
                 r.RDB$DESCRIPTION,
                 r.RDB$DEFAULT_VALUE,
-                r.RDB$NULL_FLAG.nvl((short) 0),
+                DSL.bitOr(r.RDB$NULL_FLAG.nvl((short) 0), f.RDB$NULL_FLAG.nvl((short) 0)).as(r.RDB$NULL_FLAG.getName()),
                 r.RDB$DEFAULT_SOURCE,
                 r.RDB$FIELD_POSITION,
 
@@ -140,7 +141,7 @@ public class FirebirdTableDefinition extends AbstractTableDefinition {
                     record.getValue("FIELD_LENGTH", short.class),
                     record.getValue(f.RDB$FIELD_PRECISION),
                     record.getValue("FIELD_SCALE", Integer.class),
-                    record.getValue(r.RDB$NULL_FLAG.nvl((short) 0)) == 0,
+                    record.getValue(r.RDB$NULL_FLAG) == 0,
                     record.getValue(r.RDB$DEFAULT_SOURCE) != null
             );
 
diff --git a/jOOQ-test/src/main/resources/org/jooq/test/firebird/create.sql b/jOOQ-test/src/main/resources/org/jooq/test/firebird/create.sql
index e179c05125..cc4e5a2fff 100644
--- a/jOOQ-test/src/main/resources/org/jooq/test/firebird/create.sql
+++ b/jOOQ-test/src/main/resources/org/jooq/test/firebird/create.sql
@@ -43,6 +43,10 @@ DROP TABLE t_3342/
 DROP TABLE t_identity/
 DROP TABLE t_identity_pk/
 
+DROP DOMAIN d_3382/
+
+CREATE DOMAIN d_3382 AS INT NOT NULL/
+
 
 CREATE TABLE t_dates (
   id int,
@@ -228,9 +232,9 @@ CREATE TABLE x_unused (
 /
 
 CREATE TABLE t_exotic_types (
-  ID INT NOT NULL,
+  ID d_3382 NOT NULL,
   UU CHAR(36),
-  
+
   CONSTRAINT pk_t_exotic_types PRIMARY KEY(ID)
 );
 /
@@ -283,7 +287,7 @@ CREATE TABLE x_test_case_85 (
 CREATE TABLE x_test_case_2025 (
   ref_id int NOT NULL,
   ref_name VARCHAR(10) NOT NULL,
-  
+
   CONSTRAINT fk_x_test_case_2025_1 FOREIGN KEY(ref_id) REFERENCES x_test_case_85(ID),
   CONSTRAINT fk_x_test_case_2025_2 FOREIGN KEY(ref_id) REFERENCES x_test_case_71(ID),
   CONSTRAINT fk_x_test_case_2025_3 FOREIGN KEY(ref_id, ref_name) REFERENCES X_UNUSED(id, name)