diff --git a/internal/domain/main-entities/specialist/dto.go b/internal/domain/main-entities/specialist/dto.go
index 04f848cd..1b75e7cb 100644
--- a/internal/domain/main-entities/specialist/dto.go
+++ b/internal/domain/main-entities/specialist/dto.go
@@ -7,10 +7,10 @@ import (
 )
 
 type CreateDto struct {
-	Id                *uint  `json:"id"`
-	Installation_Code string `json:"installation_code"`
-	Code              string `json:"code" validate:"maxLength=10"`
-	Name              string `json:"name" validate:"maxLength=50"`
+	Id                *uint   `json:"id"`
+	Installation_Code *string `json:"installation_code"`
+	Code              string  `json:"code" validate:"maxLength=10"`
+	Name              string  `json:"name" validate:"maxLength=50"`
 }
 
 type ReadListDto struct {
diff --git a/internal/domain/main-entities/specialist/entity.go b/internal/domain/main-entities/specialist/entity.go
index 0326f614..c53e29ec 100644
--- a/internal/domain/main-entities/specialist/entity.go
+++ b/internal/domain/main-entities/specialist/entity.go
@@ -11,7 +11,7 @@ type Specialist struct {
 	ecore.SmallMain                      // adjust this according to the needs
 	Code                string           `json:"code" gorm:"unique;size:20"`
 	Name                string           `json:"name" gorm:"size:50"`
-	Installation_Code   string           `json:"installation_code" gorm:"size:20"`
+	Installation_Code   *string          `json:"installation_code" gorm:"size:20"`
 	Installation        *ei.Installation `json:"installation,omitempty" gorm:"foreignKey:Installation_Code;references:Code"`
 	SpecialistPositions []eub.Basic      `json:"specialistPositions,omitempty" gorm:"foreignKey:Specialist_Code;references:Code"`
 	Subspecialists      []essb.Basic     `json:"subspecialists,omitempty" gorm:"foreignKey:Specialist_Code;references:Code"`