diff --git a/packages/cli/src/utils/sandbox-macos-permissive-open.sb b/packages/cli/src/utils/sandbox-macos-permissive-open.sb
index 50d21a1f35..2874e963ff 100644
--- a/packages/cli/src/utils/sandbox-macos-permissive-open.sb
+++ b/packages/cli/src/utils/sandbox-macos-permissive-open.sb
@@ -22,4 +22,6 @@
     (literal "/dev/stdout")
     (literal "/dev/stderr")
     (literal "/dev/null")
-)
\ No newline at end of file
+    (literal "/dev/ptmx")
+    (regex #"^/dev/ttys[0-9]*$")
+)
diff --git a/packages/core/src/services/shellExecutionService.ts b/packages/core/src/services/shellExecutionService.ts
index f3bdddbc55..d5dc17bb14 100644
--- a/packages/core/src/services/shellExecutionService.ts
+++ b/packages/core/src/services/shellExecutionService.ts
@@ -678,19 +678,28 @@ export class ShellExecutionService {
       return { pid: ptyProcess.pid, result };
     } catch (e) {
       const error = e as Error;
-      return {
-        pid: undefined,
-        result: Promise.resolve({
-          error,
-          rawOutput: Buffer.from(''),
-          output: '',
-          exitCode: 1,
-          signal: null,
-          aborted: false,
+      if (error.message.includes('posix_spawnp failed')) {
+        onOutputEvent({
+          type: 'data',
+          chunk:
+            '[GEMINI_CLI_WARNING] PTY execution failed, falling back to child_process. This may be due to sandbox restrictions.\n',
+        });
+        throw e;
+      } else {
+        return {
           pid: undefined,
-          executionMethod: 'none',
-        }),
-      };
+          result: Promise.resolve({
+            error,
+            rawOutput: Buffer.from(''),
+            output: '',
+            exitCode: 1,
+            signal: null,
+            aborted: false,
+            pid: undefined,
+            executionMethod: 'none',
+          }),
+        };
+      }
     }
   }