diff --git a/docs/config.png b/docs/config.png
index 0c60626b..a5e468d6 100644
Binary files a/docs/config.png and b/docs/config.png differ
diff --git a/docs/config.puml b/docs/config.puml
index 636d2268..17d14e02 100644
--- a/docs/config.puml
+++ b/docs/config.puml
@@ -73,7 +73,7 @@ class "PostgreSQLDatabaseConfiguration" as src.models.config.PostgreSQLDatabaseC
   host : str
   namespace : Optional[str]
   password : str
-  port : int
+  port : Annotated
   ssl_mode : str
   user : str
   check_postgres_configuration() -> Self
@@ -87,9 +87,9 @@ class "ServiceConfiguration" as src.models.config.ServiceConfiguration {
   color_log : bool
   cors
   host : str
-  port : int
+  port : Annotated
   tls_config
-  workers : int
+  workers : Annotated
   check_service_configuration() -> Self
 }
 class "TLSConfiguration" as src.models.config.TLSConfiguration {
diff --git a/src/models/config.py b/src/models/config.py
index bda9699a..5010a7ba 100644
--- a/src/models/config.py
+++ b/src/models/config.py
@@ -3,7 +3,7 @@
 from pathlib import Path
 from typing import Optional
 
-from pydantic import BaseModel, model_validator, FilePath, AnyHttpUrl
+from pydantic import BaseModel, model_validator, FilePath, AnyHttpUrl, PositiveInt
 from typing_extensions import Self, Literal
 
 import constants
@@ -58,7 +58,7 @@ class PostgreSQLDatabaseConfiguration(BaseModel):
     """PostgreSQL database configuration."""
 
     host: str = "localhost"
-    port: int = 5432
+    port: PositiveInt = 5432
     db: str
     user: str
     password: str
@@ -70,8 +70,6 @@ class PostgreSQLDatabaseConfiguration(BaseModel):
     @model_validator(mode="after")
     def check_postgres_configuration(self) -> Self:
         """Check PostgreSQL configuration."""
-        if self.port <= 0:
-            raise ValueError("Port value should not be negative")
         if self.port > 65535:
             raise ValueError("Port value should be less than 65536")
         if self.ca_cert_path is not None and not self.ca_cert_path.exists():
@@ -124,9 +122,9 @@ class ServiceConfiguration(BaseModel):
     """Service configuration."""
 
     host: str = "localhost"
-    port: int = 8080
+    port: PositiveInt = 8080
     auth_enabled: bool = False
-    workers: int = 1
+    workers: PositiveInt = 1
     color_log: bool = True
     access_log: bool = True
     tls_config: TLSConfiguration = TLSConfiguration()
@@ -135,12 +133,8 @@ class ServiceConfiguration(BaseModel):
     @model_validator(mode="after")
     def check_service_configuration(self) -> Self:
         """Check service configuration."""
-        if self.port <= 0:
-            raise ValueError("Port value should not be negative")
         if self.port > 65535:
             raise ValueError("Port value should be less than 65536")
-        if self.workers < 1:
-            raise ValueError("Workers must be set to at least 1")
         return self
 
 
diff --git a/tests/unit/models/test_config.py b/tests/unit/models/test_config.py
index 02a976c6..76e64bc9 100644
--- a/tests/unit/models/test_config.py
+++ b/tests/unit/models/test_config.py
@@ -48,7 +48,7 @@ def test_service_configuration_constructor() -> None:
 
 def test_service_configuration_port_value() -> None:
     """Test the ServiceConfiguration port value validation."""
-    with pytest.raises(ValueError, match="Port value should not be negative"):
+    with pytest.raises(ValidationError, match="Input should be greater than 0"):
         ServiceConfiguration(port=-1)
 
     with pytest.raises(ValueError, match="Port value should be less than 65536"):
@@ -57,7 +57,7 @@ def test_service_configuration_port_value() -> None:
 
 def test_service_configuration_workers_value() -> None:
     """Test the ServiceConfiguration workers value validation."""
-    with pytest.raises(ValueError, match="Workers must be set to at least 1"):
+    with pytest.raises(ValidationError, match="Input should be greater than 0"):
         ServiceConfiguration(workers=-1)