diff --git a/.replit b/.replit
index e5bcd37..2934391 100644
--- a/.replit
+++ b/.replit
@@ -19,6 +19,10 @@ externalPort = 80
 localPort = 33035
 externalPort = 3001
 
+[[ports]]
+localPort = 37459
+externalPort = 5173
+
 [[ports]]
 localPort = 41295
 externalPort = 6000
@@ -35,10 +39,6 @@ externalPort = 4200
 localPort = 42175
 externalPort = 3002
 
-[[ports]]
-localPort = 42423
-externalPort = 5173
-
 [[ports]]
 localPort = 43169
 externalPort = 5000
diff --git a/client/src/pages/sites.tsx b/client/src/pages/sites.tsx
index 1cd0fa2..7e9d102 100644
--- a/client/src/pages/sites.tsx
+++ b/client/src/pages/sites.tsx
@@ -49,6 +49,7 @@ export default function Sites() {
     defaultValues: {
       name: "",
       address: "",
+      customerId: undefined,
       shiftType: "fixed_post",
       minGuards: 1,
       requiresArmed: false,
@@ -67,6 +68,7 @@ export default function Sites() {
     defaultValues: {
       name: "",
       address: "",
+      customerId: undefined,
       shiftType: "fixed_post",
       minGuards: 1,
       requiresArmed: false,
@@ -139,6 +141,7 @@ export default function Sites() {
     editForm.reset({
       name: site.name,
       address: site.address,
+      customerId: site.customerId ?? undefined,
       location: site.location,
       shiftType: site.shiftType,
       minGuards: site.minGuards,
@@ -237,15 +240,14 @@ export default function Sites() {
                   name="customerId"
                   render={({ field }) => (
                     <FormItem>
-                      <FormLabel>Cliente</FormLabel>
-                      <Select onValueChange={field.onChange} value={field.value || undefined}>
+                      <FormLabel>Cliente (opzionale)</FormLabel>
+                      <Select onValueChange={(value) => field.onChange(value || undefined)} value={field.value ?? undefined}>
                         <FormControl>
                           <SelectTrigger data-testid="select-customer">
-                            <SelectValue placeholder="Seleziona cliente (opzionale)" />
+                            <SelectValue placeholder="Nessun cliente" />
                           </SelectTrigger>
                         </FormControl>
                         <SelectContent>
-                          <SelectItem value="">Nessun cliente</SelectItem>
                           {customers?.map((customer) => (
                             <SelectItem key={customer.id} value={customer.id}>
                               {customer.name}
@@ -524,15 +526,14 @@ export default function Sites() {
                 name="customerId"
                 render={({ field }) => (
                   <FormItem>
-                    <FormLabel>Cliente</FormLabel>
-                    <Select onValueChange={field.onChange} value={field.value || undefined}>
+                    <FormLabel>Cliente (opzionale)</FormLabel>
+                    <Select onValueChange={(value) => field.onChange(value || undefined)} value={field.value ?? undefined}>
                       <FormControl>
                         <SelectTrigger data-testid="select-edit-customer">
-                          <SelectValue placeholder="Seleziona cliente (opzionale)" />
+                          <SelectValue placeholder="Nessun cliente" />
                         </SelectTrigger>
                       </FormControl>
                       <SelectContent>
-                        <SelectItem value="">Nessun cliente</SelectItem>
                         {customers?.map((customer) => (
                           <SelectItem key={customer.id} value={customer.id}>
                             {customer.name}