diff --git a/civo/network/resource_network.go b/civo/network/resource_network.go
index 096d1e7..d769fd3 100644
--- a/civo/network/resource_network.go
+++ b/civo/network/resource_network.go
@@ -2,6 +2,7 @@ package network
 
 import (
 	"context"
+	"fmt"
 	"log"
 	"time"
 
@@ -96,6 +97,7 @@ func ResourceNetwork() *schema.Resource {
 		Importer: &schema.ResourceImporter{
 			StateContext: schema.ImportStatePassthroughContext,
 		},
+		CustomizeDiff: customizeDiffNetwork,
 	}
 }
 
@@ -259,3 +261,10 @@ func expandStringList(input interface{}) []string {
 	}
 	return result
 }
+
+func customizeDiffNetwork(ctx context.Context, d *schema.ResourceDiff, meta interface{}) error {
+	if d.Id() != "" && d.HasChange("cidr_v4") {
+		return fmt.Errorf("the 'cidr_v4' field is immutable")
+	}
+	return nil
+}