diff --git a/packages/services/src/page/__tests__/page.test.ts b/packages/services/src/page/__tests__/page.test.ts
index e75a08d4..d6ec3b56 100644
--- a/packages/services/src/page/__tests__/page.test.ts
+++ b/packages/services/src/page/__tests__/page.test.ts
@@ -28,7 +28,9 @@ import {
 import { createPage, newPage } from "../create";
 import { deletePage } from "../delete";
 import { getPage, getPageBySlug, getSlugAvailable, listPages } from "../list";
+import { UpdatePageConfigurationInput } from "../schemas";
 import {
+  updatePageConfiguration,
   updatePageCustomTheme,
   updatePageGeneral,
   updatePageLocales,
@@ -372,6 +374,66 @@ describe("updatePageGeneral", () => {
   });
 });
 
+describe("updatePageConfiguration", () => {
+  test("preserves omitted settings in partial updates", async () => {
+    await withTestTransaction(async (tx) => {
+      const ctx = { ...teamCtx, db: tx };
+      const p = await createPage({
+        ctx,
+        input: {
+          workspaceId: ctx.workspace.id,
+          title: "Configuration",
+          slug: uniqueSlug("configuration"),
+          description: "",
+          customDomain: "",
+          configuration: {
+            type: "manual",
+            value: "manual",
+            uptime: false,
+            theme: "default-rounded",
+            days: 30,
+          },
+        },
+      });
+
+      for (const configuration of [
+        { days: 45 },
+        {},
+        { theme: undefined },
+        null,
+        undefined,
+      ]) {
+        await updatePageConfiguration({
+          ctx,
+          input: UpdatePageConfigurationInput.parse({
+            id: p.id,
+            configuration,
+          }),
+        });
+        const row = await tx
+          .select()
+          .from(pageTable)
+          .where(eq(pageTable.id, p.id))
+          .get();
+        expect(row?.configuration).toEqual({
+          type: "manual",
+          value: "manual",
+          uptime: false,
+          theme: "default-rounded",
+          days: 45,
+        });
+      }
+      await expectAuditRow({
+        workspaceId: ctx.workspace.id,
+        action: "page.update",
+        entityType: "page",
+        entityId: p.id,
+        db: tx,
+      });
+    });
+  });
+});
+
 describe("updatePageLocales", () => {
   test("rejects when plan lacks i18n", async () => {
     await withTestTransaction(async (tx) => {
diff --git a/packages/services/src/page/schemas.ts b/packages/services/src/page/schemas.ts
index 30ee8c86..2383c018 100644
--- a/packages/services/src/page/schemas.ts
+++ b/packages/services/src/page/schemas.ts
@@ -175,16 +175,18 @@ export const UpdatePageLocalesInput = z
   );
 export type UpdatePageLocalesInput = z.infer<typeof UpdatePageLocalesInput>;
 
-// Reuse the canonical `pageConfigurationSchema` — the read path runs
-// stored configuration through it, so anything the update accepts that
-// doesn't round-trip here would surface as an opaque parse error at
-// status-page render time rather than at write time. The prior
-// `z.record(z.string(), z.union([z.string(), z.boolean()]))` happily
-// persisted any key/value and broke the read parser on values outside
-// the defined enums.
+// Match undefined before the read validators can fill in defaults.
 export const UpdatePageConfigurationInput = z.object({
   id: z.number().int(),
-  configuration: pageConfigurationSchema.nullish(),
+  configuration: z
+    .object({
+      value: z.undefined().or(pageConfigurationSchema.shape.value),
+      type: z.undefined().or(pageConfigurationSchema.shape.type),
+      uptime: z.undefined().or(pageConfigurationSchema.shape.uptime),
+      theme: z.undefined().or(pageConfigurationSchema.shape.theme),
+      days: z.undefined().or(pageConfigurationSchema.shape.days),
+    })
+    .nullish(),
 });
 export type UpdatePageConfigurationInput = z.infer<
   typeof UpdatePageConfigurationInput
diff --git a/packages/services/src/page/update.ts b/packages/services/src/page/update.ts
index 5737ddfd..06115882 100644
--- a/packages/services/src/page/update.ts
+++ b/packages/services/src/page/update.ts
@@ -13,8 +13,8 @@ import {
 import {
   UpdatePageAppearanceInput,
   UpdatePageConfigurationInput,
-  UpdatePageCustomThemeInput,
   UpdatePageCustomDomainInput,
+  UpdatePageCustomThemeInput,
   UpdatePageGeneralInput,
   UpdatePageLinksInput,
   UpdatePageLocalesInput,
@@ -346,7 +346,11 @@ export async function updatePageConfiguration(args: {
       .set({
         configuration: {
           ...currentConfiguration,
-          ...input.configuration,
+          ...Object.fromEntries(
+            Object.entries(input.configuration ?? {}).filter(
+              ([, value]) => value !== undefined,
+            ),
+          ),
         },
         updatedAt: new Date(),
       })