diff --git a/lib/modules/datasource/conda/index.spec.ts b/lib/modules/datasource/conda/index.spec.ts
index f4843f4d5aa..c3b49e1d8cf 100644
--- a/lib/modules/datasource/conda/index.spec.ts
+++ b/lib/modules/datasource/conda/index.spec.ts
@@ -76,6 +76,27 @@ describe('modules/datasource/conda/index', () => {
       expect(res).toBeNull();
     });
 
+    it('handles null html_url and dev_url without throwing', async () => {
+      const packageName = 'pytest';
+      httpMock
+        .scope('https://api.anaconda.org/package/conda-forge')
+        .get(`/${packageName}`)
+        .reply(200, {
+          html_url: null,
+          dev_url: null,
+          versions: ['1.0.0'],
+          files: [],
+        });
+      const res = await getPkgReleases({
+        registryUrls: ['https://api.anaconda.org/package/conda-forge'],
+        datasource,
+        packageName,
+      });
+      expect(res).toMatchObject({ releases: [{ version: '1.0.0' }] });
+      expect(res?.homepage).toBeUndefined();
+      expect(res?.sourceUrl).toBeUndefined();
+    });
+
     it('supports multiple custom datasource urls', async () => {
       const packageName = 'pytest';
       httpMock
diff --git a/lib/modules/datasource/conda/schema.ts b/lib/modules/datasource/conda/schema.ts
index 37e36fdae3e..5b75e703ff5 100644
--- a/lib/modules/datasource/conda/schema.ts
+++ b/lib/modules/datasource/conda/schema.ts
@@ -1,14 +1,14 @@
 import { z } from 'zod/v4';
-import { LooseArray } from '../../../util/schema-utils/index.ts';
+import { LooseArray, Nullish } from '../../../util/schema-utils/index.ts';
 
 export const CondaFile = z.object({
   version: z.string(),
-  upload_time: z.string().optional(),
+  upload_time: Nullish(z.string()),
 });
 
 export const CondaPackage = z.object({
-  html_url: z.string().optional(),
-  dev_url: z.string().optional(),
+  html_url: Nullish(z.string()),
+  dev_url: Nullish(z.string()),
   files: LooseArray(CondaFile).optional(),
   versions: z.array(z.string()).optional(),
 });
diff --git a/lib/modules/datasource/pypi/index.ts b/lib/modules/datasource/pypi/index.ts
index bde8252aec9..66d8d23d9fb 100644
--- a/lib/modules/datasource/pypi/index.ts
+++ b/lib/modules/datasource/pypi/index.ts
@@ -156,6 +156,7 @@ export class PypiDatasource extends Datasource {
         const lower = name.toLowerCase();
 
         if (
+          projectUrl &&
           !dependency.sourceUrl &&
           (lower.startsWith('repo') ||
             lower === 'code' ||
diff --git a/lib/modules/datasource/pypi/schema.spec.ts b/lib/modules/datasource/pypi/schema.spec.ts
index 6d6dc65a433..50f8ac464a2 100644
--- a/lib/modules/datasource/pypi/schema.spec.ts
+++ b/lib/modules/datasource/pypi/schema.spec.ts
@@ -21,7 +21,7 @@ describe('modules/datasource/pypi/schema', () => {
           ],
           '2.27.0': [
             {
-              requires_python: null, // null is allowed
+              requires_python: null,
               upload_time: '2021-11-16T12:00:00',
               yanked: true,
             },
@@ -31,7 +31,16 @@ describe('modules/datasource/pypi/schema', () => {
       const result = PypiResponse.parse(input);
       expect(result?.info?.name).toBe('requests');
       expect(result?.releases?.['2.28.0']?.[0].requires_python).toBe('>=3.7');
-      expect(result?.releases?.['2.27.0']?.[0].requires_python).toBeNull();
+      expect(result?.releases?.['2.27.0']?.[0].requires_python).toBeUndefined();
+    });
+
+    it('normalizes null home_page to undefined', () => {
+      const input = {
+        info: { name: 'pkg', home_page: null },
+        releases: {},
+      };
+      const result = PypiResponse.parse(input);
+      expect(result?.info?.home_page).toBeUndefined();
     });
 
     it('parses a PyPI JSON response with a null home_page', () => {
@@ -46,7 +55,7 @@ describe('modules/datasource/pypi/schema', () => {
         releases: {},
       };
       const result = PypiResponse.parse(input);
-      expect(result?.info?.home_page).toBeNull();
+      expect(result?.info?.home_page).toBeUndefined();
       expect(result?.info?.project_urls?.Repository).toBe(
         input.info.project_urls.Repository,
       );
diff --git a/lib/modules/datasource/pypi/schema.ts b/lib/modules/datasource/pypi/schema.ts
index 3051016f0da..ac1211730a6 100644
--- a/lib/modules/datasource/pypi/schema.ts
+++ b/lib/modules/datasource/pypi/schema.ts
@@ -1,9 +1,10 @@
 import { z } from 'zod/v4';
+import { Nullish } from '../../../util/schema-utils/index.ts';
 
 export const PypiRelease = z.object({
-  requires_python: z.string().nullish(),
-  upload_time: z.string().optional(),
-  yanked: z.boolean().optional(),
+  requires_python: Nullish(z.string()),
+  upload_time: Nullish(z.string()),
+  yanked: Nullish(z.boolean()).default(false),
 });
 
 export type PypiRelease = z.infer<typeof PypiRelease>;
@@ -11,9 +12,9 @@ export type PypiRelease = z.infer<typeof PypiRelease>;
 export const PypiResponse = z.object({
   info: z
     .object({
-      name: z.string().optional(),
-      home_page: z.string().optional().nullish(),
-      project_urls: z.record(z.string(), z.string()).optional(),
+      name: Nullish(z.string()),
+      home_page: Nullish(z.string()),
+      project_urls: z.record(z.string(), Nullish(z.string())).optional(),
     })
     .optional(),
   releases: z.record(z.string(), z.array(PypiRelease)).optional(),
diff --git a/lib/util/schema-utils/index.spec.ts b/lib/util/schema-utils/index.spec.ts
index d5f376d0e05..e526922c726 100644
--- a/lib/util/schema-utils/index.spec.ts
+++ b/lib/util/schema-utils/index.spec.ts
@@ -10,6 +10,7 @@ import {
   LooseRecord,
   MultidocYaml,
   NotCircular,
+  Nullish,
   Toml,
   UtcDate,
   Yaml,
@@ -141,6 +142,28 @@ describe('util/schema-utils/index', () => {
     });
   });
 
+  describe('Nullish', () => {
+    it('converts null to undefined', () => {
+      const s = z.object({ a: Nullish(z.string()) });
+      expect(s.parse({ a: null })).toEqual({});
+    });
+
+    it('converts undefined to undefined (key absent)', () => {
+      const s = z.object({ a: Nullish(z.string()) });
+      expect(s.parse({})).toEqual({});
+    });
+
+    it('preserves valid string values', () => {
+      const s = z.object({ a: Nullish(z.string()) });
+      expect(s.parse({ a: 'hello' })).toEqual({ a: 'hello' });
+    });
+
+    it('rejects wrong types', () => {
+      const s = Nullish(z.string());
+      expect(() => s.parse(42)).toThrow();
+    });
+  });
+
   describe('Json', () => {
     it('parses json', () => {
       const Schema = Json.pipe(z.object({ foo: z.literal('bar') }));
diff --git a/lib/util/schema-utils/index.ts b/lib/util/schema-utils/index.ts
index 6dc626f89dd..5c4356456f9 100644
--- a/lib/util/schema-utils/index.ts
+++ b/lib/util/schema-utils/index.ts
@@ -187,6 +187,20 @@ export function LooseRecord<
   });
 }
 
+/**
+ * Accepts `null`, `undefined`, or an absent key and normalizes all to
+ * `undefined`. Keeps the output type as `T | undefined` (never `null`), so
+ * assignment into non-nullable targets needs no `?? undefined` coalescing.
+ */
+export function Nullish<Schema extends z.ZodTypeAny>(
+  schema: Schema,
+): z.ZodOptional<z.ZodType<z.output<Schema> | undefined>> {
+  return schema
+    .nullable()
+    .transform((value) => value ?? undefined)
+    .optional();
+}
+
 export const Json = z.string().transform((str, ctx): unknown => {
   try {
     return JSON.parse(str);