diff --git a/packages/opencode/bin/opencode b/packages/opencode/bin/opencode
index 2526b0f76a05..d6801adb1b6b 100755
--- a/packages/opencode/bin/opencode
+++ b/packages/opencode/bin/opencode
@@ -25,6 +25,10 @@ function bun(dir) {
     {
       stdio: "inherit",
       cwd: dir,
+      env: {
+        ...process.env,
+        OPENCODE_ORIGINAL_CWD: process.cwd(),
+      },
     },
   )
   if (result.error) {
diff --git a/packages/opencode/src/index.ts b/packages/opencode/src/index.ts
index 1fa027abf904..8820416bad2d 100644
--- a/packages/opencode/src/index.ts
+++ b/packages/opencode/src/index.ts
@@ -37,6 +37,14 @@ import { errorMessage } from "./util/error"
 import { PluginCommand } from "./cli/cmd/plug"
 import { Heap } from "./cli/heap"
 
+// When launched via the bun fallback in bin/opencode, the subprocess CWD is set
+// to the opencode package directory (so ./src/index.ts resolves). The original
+// user CWD is passed via OPENCODE_ORIGINAL_CWD. Restore it early so all code
+// paths (including process.cwd() calls in CLI handlers) see the correct directory.
+if (process.env.OPENCODE_ORIGINAL_CWD) {
+  process.chdir(process.env.OPENCODE_ORIGINAL_CWD)
+}
+
 process.on("unhandledRejection", (e) => {
   Log.Default.error("rejection", {
     e: errorMessage(e),