diff --git a/packages/frontend-plugin-api/src/blueprints/ApiBlueprint.test.ts b/packages/frontend-plugin-api/src/blueprints/ApiBlueprint.test.ts
index fabc15b3f4..283ce66e8c 100644
--- a/packages/frontend-plugin-api/src/blueprints/ApiBlueprint.test.ts
+++ b/packages/frontend-plugin-api/src/blueprints/ApiBlueprint.test.ts
@@ -190,7 +190,6 @@ describe('ApiBlueprint', () => {
             },
           },
           "parse": [Function],
-          "schema": [Function],
         },
         "disabled": false,
         "factory": [Function],
diff --git a/packages/frontend-plugin-api/src/blueprints/NavItemBlueprint.test.tsx b/packages/frontend-plugin-api/src/blueprints/NavItemBlueprint.test.tsx
index ccdaa53a55..4efe16df12 100644
--- a/packages/frontend-plugin-api/src/blueprints/NavItemBlueprint.test.tsx
+++ b/packages/frontend-plugin-api/src/blueprints/NavItemBlueprint.test.tsx
@@ -47,7 +47,6 @@ describe('NavItemBlueprint', () => {
             },
           },
           "parse": [Function],
-          "schema": [Function],
         },
         "disabled": false,
         "factory": [Function],
diff --git a/packages/frontend-plugin-api/src/blueprints/PageBlueprint.test.tsx b/packages/frontend-plugin-api/src/blueprints/PageBlueprint.test.tsx
index 9ac58b3b06..cc043e6283 100644
--- a/packages/frontend-plugin-api/src/blueprints/PageBlueprint.test.tsx
+++ b/packages/frontend-plugin-api/src/blueprints/PageBlueprint.test.tsx
@@ -61,7 +61,6 @@ describe('PageBlueprint', () => {
             },
           },
           "parse": [Function],
-          "schema": [Function],
         },
         "disabled": false,
         "factory": [Function],
diff --git a/packages/frontend-plugin-api/src/schema/createPortableSchema.test.ts b/packages/frontend-plugin-api/src/schema/createPortableSchema.test.ts
index 7ea5943f17..55d5421adb 100644
--- a/packages/frontend-plugin-api/src/schema/createPortableSchema.test.ts
+++ b/packages/frontend-plugin-api/src/schema/createPortableSchema.test.ts
@@ -367,6 +367,18 @@ describe('createConfigSchema', () => {
       );
     });
 
+    it('should not produce undefined keys for absent optional fields', () => {
+      const schema = createConfigSchema({
+        name: z => z.string(),
+        title: z => z.string().optional(),
+        count: z => z.number().default(42),
+      });
+
+      const result = schema.parse({ name: 'hello' });
+      expect(result).toEqual({ name: 'hello', count: 42 });
+      expect(Object.keys(result as object)).toEqual(['name', 'count']);
+    });
+
     it('should not mark defaulted zod v3 fields as required in JSON Schema', () => {
       const schema = createConfigSchema({
         name: z => z.string(),
diff --git a/packages/frontend-plugin-api/src/schema/createPortableSchema.ts b/packages/frontend-plugin-api/src/schema/createPortableSchema.ts
index e1482475ef..2efa93b2e3 100644
--- a/packages/frontend-plugin-api/src/schema/createPortableSchema.ts
+++ b/packages/frontend-plugin-api/src/schema/createPortableSchema.ts
@@ -119,7 +119,7 @@ function buildPortableSchema<TOutput = unknown>(
       const validated = field.validate(inputObj[key]);
       if ('errors' in validated) {
         errors.push(...validated.errors);
-      } else {
+      } else if (validated.value !== undefined || key in inputObj) {
         result[key] = validated.value;
       }
     }
@@ -152,7 +152,7 @@ function buildPortableSchema<TOutput = unknown>(
       return cached;
     },
     configurable: true,
-    enumerable: true,
+    enumerable: false,
   });
 
   return result;
diff --git a/plugins/catalog-react/src/alpha/blueprints/EntityCardBlueprint.test.tsx b/plugins/catalog-react/src/alpha/blueprints/EntityCardBlueprint.test.tsx
index 0bf88b18c4..776c297fe0 100644
--- a/plugins/catalog-react/src/alpha/blueprints/EntityCardBlueprint.test.tsx
+++ b/plugins/catalog-react/src/alpha/blueprints/EntityCardBlueprint.test.tsx
@@ -58,7 +58,6 @@ describe('EntityCardBlueprint', () => {
             },
           },
           "parse": [Function],
-          "schema": [Function],
         },
         "disabled": false,
         "factory": [Function],
diff --git a/plugins/catalog-react/src/alpha/blueprints/EntityContentBlueprint.test.tsx b/plugins/catalog-react/src/alpha/blueprints/EntityContentBlueprint.test.tsx
index d0dff2a939..ff330473bf 100644
--- a/plugins/catalog-react/src/alpha/blueprints/EntityContentBlueprint.test.tsx
+++ b/plugins/catalog-react/src/alpha/blueprints/EntityContentBlueprint.test.tsx
@@ -75,7 +75,6 @@ describe('EntityContentBlueprint', () => {
             },
           },
           "parse": [Function],
-          "schema": [Function],
         },
         "disabled": false,
         "factory": [Function],
diff --git a/plugins/catalog-react/src/alpha/blueprints/EntityContextMenuItemBlueprint.test.tsx b/plugins/catalog-react/src/alpha/blueprints/EntityContextMenuItemBlueprint.test.tsx
index 463bc7cf60..467068c668 100644
--- a/plugins/catalog-react/src/alpha/blueprints/EntityContextMenuItemBlueprint.test.tsx
+++ b/plugins/catalog-react/src/alpha/blueprints/EntityContextMenuItemBlueprint.test.tsx
@@ -71,7 +71,6 @@ describe('EntityContextMenuItemBlueprint', () => {
             },
           },
           "parse": [Function],
-          "schema": [Function],
         },
         "disabled": false,
         "factory": [Function],
diff --git a/plugins/search-react/src/alpha/blueprints/SearchResultListItemBlueprint.test.tsx b/plugins/search-react/src/alpha/blueprints/SearchResultListItemBlueprint.test.tsx
index 847a1df635..fe3fd29fc3 100644
--- a/plugins/search-react/src/alpha/blueprints/SearchResultListItemBlueprint.test.tsx
+++ b/plugins/search-react/src/alpha/blueprints/SearchResultListItemBlueprint.test.tsx
@@ -53,7 +53,6 @@ describe('SearchResultListItemBlueprint', () => {
             },
           },
           "parse": [Function],
-          "schema": [Function],
         },
         "disabled": false,
         "factory": [Function],