diff --git a/.gitignore b/.gitignore
index 0e471ec..9b01109 100644
--- a/.gitignore
+++ b/.gitignore
@@ -5,4 +5,5 @@ coverage.txt
 
 dist
 .release-env
-unit_coverage.out
\ No newline at end of file
+unit_coverage.out
+.mgr8
\ No newline at end of file
diff --git a/domain/column_diff.go b/domain/column_diff.go
index 2d79afe..1bdbd06 100644
--- a/domain/column_diff.go
+++ b/domain/column_diff.go
@@ -71,3 +71,22 @@ func (m *MakeColumnNullableDiff) Up(deparser Deparser) string {
 func (m *MakeColumnNullableDiff) Down(deparser Deparser) string {
 	return deparser.MakeColumnNotNull(m.tableName, m.columnName, m.column)
 }
+
+type ChangeColumnDataTypeParameterDiff struct {
+	tableName      string
+	columnName     string
+	originalColumn *Column
+	column         *Column
+}
+
+func NewChangeColumnParameterDiff(tableName string, columnName string, originalColumn *Column, column *Column) *ChangeColumnDataTypeParameterDiff {
+	return &ChangeColumnDataTypeParameterDiff{tableName: tableName, columnName: columnName, originalColumn: originalColumn, column: column}
+}
+
+func (m *ChangeColumnDataTypeParameterDiff) Up(deparser Deparser) string {
+	return deparser.ChangeDataTypeParameters(m.tableName, m.columnName, m.column)
+}
+
+func (m *ChangeColumnDataTypeParameterDiff) Down(deparser Deparser) string {
+	return deparser.ChangeDataTypeParameters(m.tableName, m.columnName, m.originalColumn)
+}
diff --git a/domain/diff.go b/domain/diff.go
index 9cbd131..e2a7b3c 100644
--- a/domain/diff.go
+++ b/domain/diff.go
@@ -1,5 +1,7 @@
 package domain
 
+import "reflect"
+
 type Diff interface {
 	Up(driver Deparser) string
 	Down(driver Deparser) string
@@ -50,6 +52,11 @@ func (t *Table) Diff(originalTable *Table) DiffDeque {
 func (c *Column) Diff(table *Table, columnName string, originalColumn *Column) DiffDeque {
 	diffsQueue := NewDiffDeque()
 	column := table.Columns[columnName]
+
+	if !reflect.DeepEqual(column.Parameters, originalColumn.Parameters) {
+		diffsQueue.Add(NewChangeColumnParameterDiff(table.Name, columnName, originalColumn, column))
+	}
+
 	if column.IsNotNull != originalColumn.IsNotNull {
 		if column.IsNotNull {
 			diffsQueue.Add(NewMakeColumnNotNullDiff(table.Name, columnName, column))
@@ -57,5 +64,6 @@ func (c *Column) Diff(table *Table, columnName string, originalColumn *Column) D
 			diffsQueue.Add(NewMakeColumnNullableDiff(table.Name, columnName, column))
 		}
 	}
+
 	return diffsQueue
 }
diff --git a/domain/driver.go b/domain/driver.go
index 4231a5e..b835558 100644
--- a/domain/driver.go
+++ b/domain/driver.go
@@ -38,5 +38,7 @@ type Deparser interface {
 	MakeColumnNotNull(tableName, columnName string, column *Column) string
 	MakeColumnNullable(tableName, columnName string, column *Column) string
 
+	ChangeDataTypeParameters(tableName, columnName string, column *Column) string
+
 	WriteScript(statements []string) string
 }
diff --git a/drivers/mysql/deparser.go b/drivers/mysql/deparser.go
index 72d80c3..194c694 100644
--- a/drivers/mysql/deparser.go
+++ b/drivers/mysql/deparser.go
@@ -61,6 +61,16 @@ func (d *deparser) MakeColumnNullable(tableName, columnName string, column *doma
 	return fmt.Sprintf("ALTER TABLE %s MODIFY %s NULL", tableName, columnDatatype)
 }
 
+func (d *deparser) ChangeDataTypeParameters(tableName, columnName string, column *domain.Column) string {
+	_, hasSize := column.Parameters["size"]
+
+	if hasSize {
+		return fmt.Sprintf("ALTER TABLE %s MODIFY %s %s(%s)", tableName, columnName, column.Datatype, fmt.Sprint(column.Parameters["size"]))
+	} else {
+		return fmt.Sprintf("ALTER TABLE %s MODIFY %s %s(%s, %s)", tableName, columnName, column.Datatype, fmt.Sprint(column.Parameters["precision"]), fmt.Sprint(column.Parameters["scale"]))
+	}
+}
+
 func (d *deparser) WriteScript(statements []string) string {
 	var scriptContent string
 	for _, s := range statements {
diff --git a/drivers/postgres/deparser.go b/drivers/postgres/deparser.go
index 33a6646..f1e7c30 100644
--- a/drivers/postgres/deparser.go
+++ b/drivers/postgres/deparser.go
@@ -58,14 +58,14 @@ func (d *deparser) CreateTable(table *domain.Table) string {
 		}
 
 		if column.IsNotNull {
-			statement = statement + fmt.Sprintf(" NOT NULL")
+			statement = statement + " NOT NULL"
 		}
 
-		statement = statement + fmt.Sprintf(",\n")
+		statement = statement + ",\n"
 	}
 
 	statement = statement[0 : len(statement)-2]
-	statement = statement + fmt.Sprintf("\n)")
+	statement = statement + "\n)"
 	return statement
 }
 
@@ -87,6 +87,7 @@ func (d *deparser) AddColumn(tableName, columnName string, column *domain.Column
 func (d *deparser) DropColumn(tableName, columnName string) string {
 	return fmt.Sprintf("ALTER TABLE %s DROP COLUMN %s", tableName, columnName)
 }
+
 func (d *deparser) MakeColumnNotNull(tableName, columnName string, column *domain.Column) string {
 	return fmt.Sprintf("ALTER TABLE %s ALTER COLUMN %s SET NOT NULL", tableName, columnName)
 }
@@ -95,6 +96,16 @@ func (d *deparser) MakeColumnNullable(tableName, columnName string, column *doma
 	return fmt.Sprintf("ALTER TABLE %s ALTER COLUMN %s DROP NOT NULL", tableName, columnName)
 }
 
+func (d *deparser) ChangeDataTypeParameters(tableName, columnName string, column *domain.Column) string {
+	_, hasSize := column.Parameters["size"]
+
+	if hasSize {
+		return fmt.Sprintf("ALTER TABLE %s ALTER COLUMN %s TYPE %s(%s)", tableName, columnName, column.Datatype, fmt.Sprint(column.Parameters["size"]))
+	} else {
+		return fmt.Sprintf("ALTER TABLE %s ALTER COLUMN %s TYPE %s(%s, %s)", tableName, columnName, column.Datatype, fmt.Sprint(column.Parameters["precision"]), fmt.Sprint(column.Parameters["scale"]))
+	}
+}
+
 func (d *deparser) WriteScript(statements []string) string {
 	var scriptContent string
 	for _, s := range statements {
diff --git a/drivers/postgres/parser.go b/drivers/postgres/parser.go
index 5f15f3b..1cad026 100644
--- a/drivers/postgres/parser.go
+++ b/drivers/postgres/parser.go
@@ -265,10 +265,15 @@ func (d *postgresDriver) parseColumn(columnDefinition *pg_query.ColumnDef) *doma
 	datatype := columnDefinition.TypeName.Names[1].GetString_().GetStr()
 	parameters := make(map[string]interface{})
 
-	if datatype == "varchar" {
+	if hasSingleArg(datatype) {
 		parameters["size"] = columnDefinition.TypeName.Typmods[0].GetAConst().Val.GetInteger().Ival
 	}
 
+	if hasDoubleArg(datatype) {
+		parameters["precision"] = columnDefinition.TypeName.Typmods[0].GetAConst().Val.GetInteger().Ival
+		parameters["scale"] = columnDefinition.TypeName.Typmods[1].GetAConst().Val.GetInteger().Ival
+	}
+
 	isNotNull := false
 	for _, constraint := range columnDefinition.Constraints {
 		if constraint.GetConstraint().GetContype().String() == "CONSTR_NOTNULL" {
diff --git a/drivers/postgres/postgres_test.go b/drivers/postgres/postgres_test.go
index cac4090..27efb96 100644
--- a/drivers/postgres/postgres_test.go
+++ b/drivers/postgres/postgres_test.go
@@ -26,9 +26,10 @@ var _ = Describe("Postgres Driver", func() {
 				CREATE TABLE users (
 					social_number VARCHAR(9) PRIMARY KEY,
 					phone VARCHAR(11),
-					name VARCHAR(15),
+					name VARCHAR(15) NOT NULL,
 					age INTEGER,
 					size INT,
+					height DECIMAL(2, 3),
 					ddi VARCHAR(3)
 				);
 
@@ -44,10 +45,11 @@ var _ = Describe("Postgres Driver", func() {
 							Columns: map[string]*domain.Column{
 								"social_number": {Datatype: "varchar", IsNotNull: false, Parameters: map[string]interface{}{"size": int32(9)}},
 								"phone":         {Datatype: "varchar", IsNotNull: false, Parameters: map[string]interface{}{"size": int32(11)}},
-								"name":          {Datatype: "varchar", IsNotNull: false, Parameters: map[string]interface{}{"size": int32(15)}},
+								"name":          {Datatype: "varchar", IsNotNull: true, Parameters: map[string]interface{}{"size": int32(15)}},
 								"ddi":           {Datatype: "varchar", IsNotNull: false, Parameters: map[string]interface{}{"size": int32(3)}},
 								"age":           {Datatype: "int4", IsNotNull: false, Parameters: map[string]interface{}{}},
 								"size":          {Datatype: "int4", IsNotNull: false, Parameters: map[string]interface{}{}},
+								"height":        {Datatype: "numeric", IsNotNull: false, Parameters: map[string]interface{}{"precision": int32(2), "scale": int32(3)}},
 							},
 						},
 					},
@@ -128,6 +130,24 @@ var _ = Describe("Postgres Driver", func() {
 			})
 		})
 
+		When("A column's datatype parameters change", func() {
+			It("Changes single parameter datatype", func() {
+				columnName := "col"
+				tableName := "tbl"
+				column := &domain.Column{Datatype: "varchar", IsNotNull: false, Parameters: map[string]interface{}{"size": int32(10)}}
+				stmt := subject.ChangeDataTypeParameters(tableName, columnName, column)
+				Expect(strings.ToLower(stmt)).To(Equal("alter table tbl alter column col type varchar(10)"))
+			})
+
+			It("Changes double parameter datatype", func() {
+				columnName := "col"
+				tableName := "tbl"
+				column := &domain.Column{Datatype: "decimal", IsNotNull: false, Parameters: map[string]interface{}{"precision": int32(2), "scale": int32(3)}}
+				stmt := subject.ChangeDataTypeParameters(tableName, columnName, column)
+				Expect(strings.ToLower(stmt)).To(Equal("alter table tbl alter column col type decimal(2, 3)"))
+			})
+		})
+
 		When("New schema doesn't have a table", func() {
 			It("Drops the table", func() {
 				tableName := "tbl"
diff --git a/mock/domain/driver_mock.go b/mock/domain/driver_mock.go
index 9d67e6e..5c81e93 100644
--- a/mock/domain/driver_mock.go
+++ b/mock/domain/driver_mock.go
@@ -329,6 +329,20 @@ func (mr *MockDeparserMockRecorder) AddColumn(tableName, columnName, column inte
 	return mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "AddColumn", reflect.TypeOf((*MockDeparser)(nil).AddColumn), tableName, columnName, column)
 }
 
+// ChangeDataTypeParameters mocks base method.
+func (m *MockDeparser) ChangeDataTypeParameters(tableName, columnName string, column *domain.Column) string {
+	m.ctrl.T.Helper()
+	ret := m.ctrl.Call(m, "ChangeDataTypeParameters", tableName, columnName, column)
+	ret0, _ := ret[0].(string)
+	return ret0
+}
+
+// ChangeDataTypeParameters indicates an expected call of ChangeDataTypeParameters.
+func (mr *MockDeparserMockRecorder) ChangeDataTypeParameters(tableName, columnName, column interface{}) *gomock.Call {
+	mr.mock.ctrl.T.Helper()
+	return mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "ChangeDataTypeParameters", reflect.TypeOf((*MockDeparser)(nil).ChangeDataTypeParameters), tableName, columnName, column)
+}
+
 // CreateTable mocks base method.
 func (m *MockDeparser) CreateTable(table *domain.Table) string {
 	m.ctrl.T.Helper()
diff --git a/testdata/0000_schema.sql b/testdata/0000_schema.sql
new file mode 100644
index 0000000..e69de29
diff --git a/testdata/0001_schema.sql b/testdata/0001_schema.sql
new file mode 100644
index 0000000..065bb77
--- /dev/null
+++ b/testdata/0001_schema.sql
@@ -0,0 +1,12 @@
+CREATE TABLE users (
+    social_number VARCHAR(9) PRIMARY KEY,
+    nombre VARCHAR(20) NOT NULL,
+    phone VARCHAR(20),
+    ddi VARCHAR(20),
+    num DECIMAL(20, 10)
+);
+
+CREATE TABLE products (
+   nombre VARCHAR(256),
+   qnt INTEGER
+);
diff --git a/testdata/0002_schema.sql b/testdata/0002_schema.sql
new file mode 100644
index 0000000..6c1b6ab
--- /dev/null
+++ b/testdata/0002_schema.sql
@@ -0,0 +1,6 @@
+CREATE TABLE users (
+    social_number VARCHAR(9) PRIMARY KEY,
+    nombre VARCHAR(15),
+    phone VARCHAR(11),
+    num DECIMAL(10, 5)
+);
diff --git a/testdata/new_schema.sql b/testdata/new_schema.sql
deleted file mode 100644
index a18c75b..0000000
--- a/testdata/new_schema.sql
+++ /dev/null
@@ -1,11 +0,0 @@
-CREATE TABLE users (
-    social_number VARCHAR(9) PRIMARY KEY,
-    name VARCHAR(15),
-    phone VARCHAR(11),
-    ddi VARCHAR(3)
-);
-
-CREATE TABLE products (
-   name VARCHAR(256),
-   qnt INTEGER
-);
diff --git a/testdata/old_schema.sql b/testdata/old_schema.sql
deleted file mode 100644
index 38363bd..0000000
--- a/testdata/old_schema.sql
+++ /dev/null
@@ -1,5 +0,0 @@
-CREATE TABLE users (
-    social_number VARCHAR(9) PRIMARY KEY,
-    name VARCHAR(15),
-    phone VARCHAR(11)
-);
diff --git a/testdata/output/0001_1656197671.down.sql b/testdata/output/0001_1656197671.down.sql
new file mode 100644
index 0000000..c99ddcd
--- /dev/null
+++ b/testdata/output/0001_1656197671.down.sql
@@ -0,0 +1 @@
+DROP TABLE IF EXISTS users;
diff --git a/testdata/output/0001_1656197671.up.sql b/testdata/output/0001_1656197671.up.sql
new file mode 100644
index 0000000..725c493
--- /dev/null
+++ b/testdata/output/0001_1656197671.up.sql
@@ -0,0 +1,6 @@
+CREATE TABLE users (
+nombre varchar(15),
+num numeric(10,5),
+phone varchar(11),
+social_number varchar(9)
+);
diff --git a/testdata/output/0002_1656197676.down.sql b/testdata/output/0002_1656197676.down.sql
new file mode 100644
index 0000000..a2c3974
--- /dev/null
+++ b/testdata/output/0002_1656197676.down.sql
@@ -0,0 +1,6 @@
+ALTER TABLE users DROP COLUMN ddi;
+ALTER TABLE users ALTER COLUMN num TYPE numeric(10, 5);
+ALTER TABLE users ALTER COLUMN nombre TYPE varchar(15);
+ALTER TABLE users ALTER COLUMN nombre DROP NOT NULL;
+ALTER TABLE users ALTER COLUMN phone TYPE varchar(11);
+DROP TABLE IF EXISTS products;
diff --git a/testdata/output/0002_1656197676.up.sql b/testdata/output/0002_1656197676.up.sql
new file mode 100644
index 0000000..36359ca
--- /dev/null
+++ b/testdata/output/0002_1656197676.up.sql
@@ -0,0 +1,9 @@
+ALTER TABLE users ADD COLUMN ddi varchar(20);
+ALTER TABLE users ALTER COLUMN num TYPE numeric(20, 10);
+ALTER TABLE users ALTER COLUMN nombre TYPE varchar(20);
+ALTER TABLE users ALTER COLUMN nombre SET NOT NULL;
+ALTER TABLE users ALTER COLUMN phone TYPE varchar(20);
+CREATE TABLE products (
+nombre varchar(256),
+qnt int4
+);
diff --git a/testdata/output/down_migration.sql b/testdata/output/down_migration.sql
deleted file mode 100644
index fd69ec0..0000000
--- a/testdata/output/down_migration.sql
+++ /dev/null
@@ -1,2 +0,0 @@
-DROP TABLE IF EXISTS products;
-ALTER TABLE users DROP COLUMN ddi;
diff --git a/testdata/output/up_migration.sql b/testdata/output/up_migration.sql
deleted file mode 100644
index 6467050..0000000
--- a/testdata/output/up_migration.sql
+++ /dev/null
@@ -1,2 +0,0 @@
-;
-;