diff --git a/azurerm/internal/services/postgres/postgresql_firewall_rule_resource.go b/azurerm/internal/services/postgres/postgresql_firewall_rule_resource.go
index 93fd150c1720..e51133b5f960 100644
--- a/azurerm/internal/services/postgres/postgresql_firewall_rule_resource.go
+++ b/azurerm/internal/services/postgres/postgresql_firewall_rule_resource.go
@@ -10,6 +10,7 @@ import (
 	"github.com/hashicorp/terraform-plugin-sdk/helper/schema"
 	"github.com/terraform-providers/terraform-provider-azurerm/azurerm/helpers/azure"
 	"github.com/terraform-providers/terraform-provider-azurerm/azurerm/helpers/tf"
+	azValidate "github.com/terraform-providers/terraform-provider-azurerm/azurerm/helpers/validate"
 	"github.com/terraform-providers/terraform-provider-azurerm/azurerm/internal/clients"
 	"github.com/terraform-providers/terraform-provider-azurerm/azurerm/internal/services/postgres/validate"
 	"github.com/terraform-providers/terraform-provider-azurerm/azurerm/internal/timeouts"
@@ -49,15 +50,17 @@ func resourceArmPostgreSQLFirewallRule() *schema.Resource {
 			},
 
 			"start_ip_address": {
-				Type:     schema.TypeString,
-				Required: true,
-				ForceNew: true,
+				Type:         schema.TypeString,
+				Required:     true,
+				ForceNew:     true,
+				ValidateFunc: azValidate.IPv4Address,
 			},
 
 			"end_ip_address": {
-				Type:     schema.TypeString,
-				Required: true,
-				ForceNew: true,
+				Type:         schema.TypeString,
+				Required:     true,
+				ForceNew:     true,
+				ValidateFunc: azValidate.IPv4Address,
 			},
 		},
 	}