diff --git a/packages/opencode/src/session/session.ts b/packages/opencode/src/session/session.ts
index 797a635eeef8..7e3abe75a2e0 100644
--- a/packages/opencode/src/session/session.ts
+++ b/packages/opencode/src/session/session.ts
@@ -18,6 +18,7 @@ import { like } from "drizzle-orm"
 import { inArray } from "drizzle-orm"
 import { lt } from "drizzle-orm"
 import { or } from "drizzle-orm"
+import { sql } from "drizzle-orm"
 import { SyncEvent } from "../sync"
 import type { SQL } from "drizzle-orm"
 import { PartTable, SessionTable } from "./session.sql"
@@ -49,6 +50,22 @@ function createDefaultTitle(isChild = false) {
   return (isChild ? childTitlePrefix : parentTitlePrefix) + new Date().toISOString()
 }
 
+function isWindowsDirectory(directory: string) {
+  return directory.length > 1 && (directory[1] === ":" || directory.startsWith("\\\\"))
+}
+
+function normalizeDirectory(directory: string) {
+  if (isWindowsDirectory(directory)) {
+    return directory.replaceAll("\\", "/")
+  }
+  return directory
+}
+
+function directoryMatches(directory: string) {
+  if (!isWindowsDirectory(directory)) return eq(SessionTable.directory, directory)
+  return sql`replace(${SessionTable.directory}, ${"\\"}, ${"/"}) = ${normalizeDirectory(directory)}`
+}
+
 export function isDefaultTitle(title: string) {
   return new RegExp(
     `^(${parentTitlePrefix}|${childTitlePrefix})\\d{4}-\\d{2}-\\d{2}T\\d{2}:\\d{2}:\\d{2}\\.\\d{3}Z$`,
@@ -536,7 +553,7 @@ export const layer: Layer.Layer<
         slug: Slug.create(),
         version: InstallationVersion,
         projectID: ctx.project.id,
-        directory: input.directory,
+        directory: normalizeDirectory(input.directory),
         path: input.path,
         workspaceID: input.workspaceID,
         parentID: input.parentID,
@@ -904,13 +921,13 @@ function* listByProject(
 
       conditions.push(
         input.directory
-          ? or(...conds, and(isNull(SessionTable.path), eq(SessionTable.directory, input.directory))!)!
+          ? or(...conds, and(isNull(SessionTable.path), directoryMatches(input.directory))!)!
           : or(...conds)!,
       )
     }
   } else if (input.scope !== "project" && !input.experimentalWorkspaces) {
     if (input.directory) {
-      conditions.push(eq(SessionTable.directory, input.directory))
+      conditions.push(directoryMatches(input.directory))
     }
   }
   if (input.roots) {
@@ -951,7 +968,7 @@ export function* listGlobal(input?: {
   const conditions: SQL[] = []
 
   if (input?.directory) {
-    conditions.push(eq(SessionTable.directory, input.directory))
+    conditions.push(directoryMatches(input.directory))
   }
   if (input?.roots) {
     conditions.push(isNull(SessionTable.parent_id))
diff --git a/packages/opencode/test/server/global-session-list.test.ts b/packages/opencode/test/server/global-session-list.test.ts
index 0fdba1f66397..f951ad0c89fd 100644
--- a/packages/opencode/test/server/global-session-list.test.ts
+++ b/packages/opencode/test/server/global-session-list.test.ts
@@ -6,6 +6,9 @@ import { CrossSpawnSpawner } from "@opencode-ai/core/cross-spawn-spawner"
 import * as Log from "@opencode-ai/core/util/log"
 import { provideInstance, TestInstance, tmpdirScoped } from "../fixture/fixture"
 import { testEffect } from "../lib/effect"
+import { Database } from "@/storage/db"
+import { SessionTable } from "@/session/session.sql"
+import { eq } from "drizzle-orm"
 
 void Log.init({ print: false })
 
@@ -101,4 +104,30 @@ describe("session.listGlobal", () => {
       }),
     { git: true },
   )
+
+  it.instance(
+    "matches Windows directories across separator styles",
+    () =>
+      Effect.gen(function* () {
+        const created = yield* withSession({ title: "windows-global-directory" })
+        const storedDirectory = String.raw`C:\Users\demo\project`
+        const requestedDirectory = "C:/Users/demo/project"
+
+        yield* Effect.sync(() =>
+          Database.use((db) =>
+            db
+              .update(SessionTable)
+              .set({ directory: storedDirectory, path: null })
+              .where(eq(SessionTable.id, created.id))
+              .run(),
+          ),
+        )
+
+        const sessions = yield* Effect.sync(() => [...SessionNs.listGlobal({ directory: requestedDirectory })])
+        const ids = sessions.map((session) => session.id)
+
+        expect(ids).toContain(created.id)
+      }),
+    { git: true },
+  )
 })
diff --git a/packages/opencode/test/server/session-list.test.ts b/packages/opencode/test/server/session-list.test.ts
index 4aab0c4b1f37..302d82d92146 100644
--- a/packages/opencode/test/server/session-list.test.ts
+++ b/packages/opencode/test/server/session-list.test.ts
@@ -95,6 +95,33 @@ describe("session.list", () => {
     { git: true },
   )
 
+  it.instance(
+    "matches Windows directories across separator styles",
+    () =>
+      Effect.gen(function* () {
+        const created = yield* withSession({ title: "windows-directory" })
+        const storedDirectory = String.raw`C:\Users\demo\project`
+        const requestedDirectory = "C:/Users/demo/project"
+
+        yield* Effect.sync(() =>
+          Database.use((db) =>
+            db
+              .update(SessionTable)
+              .set({ directory: storedDirectory, path: null })
+              .where(eq(SessionTable.id, created.id))
+              .run(),
+          ),
+        )
+
+        const ids = (yield* SessionNs.Service.use((session) => session.list({ directory: requestedDirectory }))).map(
+          (session) => session.id,
+        )
+
+        expect(ids).toContain(created.id)
+      }),
+    { git: true },
+  )
+
   it.instance(
     "filters by path and ignores directory when path is provided",
     () =>