diff --git a/src/config/io.write-config.test.ts b/src/config/io.write-config.test.ts
index 216d08eafb8..75eeaaac0c4 100644
--- a/src/config/io.write-config.test.ts
+++ b/src/config/io.write-config.test.ts
@@ -110,6 +110,68 @@ describe("config io write", () => {
     });
   });
 
+  it("does not reintroduce Slack/Discord legacy dm.policy defaults when writing", async () => {
+    await withTempHome("openclaw-config-io-", async (home) => {
+      const configPath = path.join(home, ".openclaw", "openclaw.json");
+      await fs.mkdir(path.dirname(configPath), { recursive: true });
+      await fs.writeFile(
+        configPath,
+        JSON.stringify(
+          {
+            channels: {
+              discord: {
+                dmPolicy: "pairing",
+                dm: { enabled: true, policy: "pairing" },
+              },
+              slack: {
+                dmPolicy: "pairing",
+                dm: { enabled: true, policy: "pairing" },
+              },
+            },
+            gateway: { port: 18789 },
+          },
+          null,
+          2,
+        ),
+        "utf-8",
+      );
+
+      const io = createConfigIO({
+        env: {} as NodeJS.ProcessEnv,
+        homedir: () => home,
+        logger: silentLogger,
+      });
+
+      const snapshot = await io.readConfigFileSnapshot();
+      expect(snapshot.valid).toBe(true);
+
+      const next = structuredClone(snapshot.config);
+      // Simulate doctor removing legacy keys while keeping dm enabled.
+      if (next.channels?.discord?.dm && typeof next.channels.discord.dm === "object") {
+        // eslint-disable-next-line @typescript-eslint/no-explicit-any -- test helper
+        delete (next.channels.discord.dm as any).policy;
+      }
+      if (next.channels?.slack?.dm && typeof next.channels.slack.dm === "object") {
+        // eslint-disable-next-line @typescript-eslint/no-explicit-any -- test helper
+        delete (next.channels.slack.dm as any).policy;
+      }
+
+      await io.writeConfigFile(next);
+
+      const persisted = JSON.parse(await fs.readFile(configPath, "utf-8")) as {
+        channels?: {
+          discord?: { dm?: Record<string, unknown>; dmPolicy?: unknown };
+          slack?: { dm?: Record<string, unknown>; dmPolicy?: unknown };
+        };
+      };
+
+      expect(persisted.channels?.discord?.dmPolicy).toBe("pairing");
+      expect(persisted.channels?.discord?.dm).toEqual({ enabled: true });
+      expect(persisted.channels?.slack?.dmPolicy).toBe("pairing");
+      expect(persisted.channels?.slack?.dm).toEqual({ enabled: true });
+    });
+  });
+
   it("keeps env refs in arrays when appending entries", async () => {
     await withTempHome("openclaw-config-io-", async (home) => {
       const configPath = path.join(home, ".openclaw", "openclaw.json");
diff --git a/src/config/zod-schema.providers-core.ts b/src/config/zod-schema.providers-core.ts
index 632b86d1190..88bbe934b9a 100644
--- a/src/config/zod-schema.providers-core.ts
+++ b/src/config/zod-schema.providers-core.ts
@@ -211,7 +211,7 @@ export const TelegramConfigSchema = TelegramAccountSchemaBase.extend({
 export const DiscordDmSchema = z
   .object({
     enabled: z.boolean().optional(),
-    policy: DmPolicySchema.optional().default("pairing"),
+    policy: DmPolicySchema.optional(),
     allowFrom: z.array(z.union([z.string(), z.number()])).optional(),
     groupEnabled: z.boolean().optional(),
     groupChannels: z.array(z.union([z.string(), z.number()])).optional(),
@@ -459,7 +459,7 @@ export const GoogleChatConfigSchema = GoogleChatAccountSchema.extend({
 export const SlackDmSchema = z
   .object({
     enabled: z.boolean().optional(),
-    policy: DmPolicySchema.optional().default("pairing"),
+    policy: DmPolicySchema.optional(),
     allowFrom: z.array(z.union([z.string(), z.number()])).optional(),
     groupEnabled: z.boolean().optional(),
     groupChannels: z.array(z.union([z.string(), z.number()])).optional(),