diff --git a/src/app/store/reservedip/types/base.ts b/src/app/store/reservedip/types/base.ts
index 5f00442172..2266cf2ff5 100644
--- a/src/app/store/reservedip/types/base.ts
+++ b/src/app/store/reservedip/types/base.ts
@@ -6,7 +6,7 @@ import type { GenericState } from "@/app/store/types/state";
 
 export type ReservedIp = TimestampedModel & {
   ip: string;
-  mac_address?: string;
+  mac_address: string;
   comment?: string;
   subnet: Subnet[SubnetMeta.PK];
   node_summary?: ReservedIpNodeSummary;
diff --git a/src/app/subnets/views/SubnetDetails/StaticDHCPLease/ReserveDHCPLease/ReserveDHCPLease.test.tsx b/src/app/subnets/views/SubnetDetails/StaticDHCPLease/ReserveDHCPLease/ReserveDHCPLease.test.tsx
index 87a94ada2d..71f236cdb3 100644
--- a/src/app/subnets/views/SubnetDetails/StaticDHCPLease/ReserveDHCPLease/ReserveDHCPLease.test.tsx
+++ b/src/app/subnets/views/SubnetDetails/StaticDHCPLease/ReserveDHCPLease/ReserveDHCPLease.test.tsx
@@ -76,6 +76,24 @@ it("displays an error if an out-of-range IP address is entered", async () => {
   ).toBeInTheDocument();
 });
 
+it("displays an error if the IP address or the MAC address are not entered", async () => {
+  state.subnet.items = [factory.subnet({ id: 1, cidr: "10.0.0.0/25" })];
+  renderWithBrowserRouter(
+    <ReserveDHCPLease
+      setSidePanelContent={vi.fn()}
+      subnetId={state.subnet.items[0].id}
+    />,
+    { state }
+  );
+
+  await userEvent.click(screen.getByRole("textbox", { name: "IP address" }));
+  await userEvent.click(screen.getByRole("textbox", { name: "MAC address" }));
+  await userEvent.tab();
+
+  expect(screen.getByText("IP address is required")).toBeInTheDocument();
+  expect(screen.getByText("MAC address is required")).toBeInTheDocument();
+});
+
 it("closes the side panel when the cancel button is clicked", async () => {
   const setSidePanelContent = vi.fn();
   renderWithBrowserRouter(
@@ -202,7 +220,7 @@ it("pre-fills the form if a reserved IPv6 address's ID is present", async () =>
   );
 });
 
-it("disables the IP address field when editing a lease", async () => {
+it("disables the IP address and MAC address fields when editing a lease", async () => {
   const reservedIp = factory.reservedIp({
     id: 1,
     ip: "10.0.0.69",
@@ -226,6 +244,7 @@ it("disables the IP address field when editing a lease", async () => {
   );
 
   expect(screen.getByRole("textbox", { name: "IP address" })).toBeDisabled();
+  expect(screen.getByRole("textbox", { name: "MAC address" })).toBeDisabled();
 });
 
 it("dispatches an action to update a reserved IP", async () => {
diff --git a/src/app/subnets/views/SubnetDetails/StaticDHCPLease/ReserveDHCPLease/ReserveDHCPLease.tsx b/src/app/subnets/views/SubnetDetails/StaticDHCPLease/ReserveDHCPLease/ReserveDHCPLease.tsx
index feea2f8ba9..1172dc9fae 100644
--- a/src/app/subnets/views/SubnetDetails/StaticDHCPLease/ReserveDHCPLease/ReserveDHCPLease.tsx
+++ b/src/app/subnets/views/SubnetDetails/StaticDHCPLease/ReserveDHCPLease/ReserveDHCPLease.tsx
@@ -148,7 +148,9 @@ const ReserveDHCPLease = ({
           );
         },
       }),
-    mac_address: Yup.string().matches(MAC_ADDRESS_REGEX, "Invalid MAC address"),
+    mac_address: Yup.string()
+      .required("MAC address is required")
+      .matches(MAC_ADDRESS_REGEX, "Invalid MAC address"),
     comment: Yup.string(),
   });
 
@@ -210,7 +212,17 @@ const ReserveDHCPLease = ({
             name="ip_address"
             required
           />
-          <MacAddressField label="MAC address" name="mac_address" />
+          <MacAddressField
+            disabled={!!reservedIpId}
+            help={
+              !!reservedIpId
+                ? "You cannot edit a reserved IP's MAC address."
+                : null
+            }
+            label="MAC address"
+            name="mac_address"
+            required
+          />
           <FormikField
             className="u-margin-bottom--x-small"
             label="Comment"