1 files changed, 13 insertions, 0 deletions
diff --git a/src/pane.rs b/src/pane.rs
index 0ba411d0..c56cfbb3 100644
--- a/src/pane.rs
+++ b/src/pane.rs
@@ -147,6 +147,9 @@ impl PaneLaunchEnv {
 
 fn apply_pane_launch_env(cmd: &mut CommandBuilder, launch_env: &PaneLaunchEnv) {
     cmd.env_remove("CODEX_THREAD_ID");
+    // OMP sets OMPCODE for shells it spawns. A pane launched from inside OMP
+    // must not inherit it or its root agent would look like a nested session.
+    cmd.env_remove("OMPCODE");
     for (key, value) in &launch_env.extra {
         cmd.env(key, value);
     }
@@ -3558,6 +3561,16 @@ mod tests {
     }
 
     #[test]
+    fn pane_launch_env_removes_outer_ompcode_marker() {
+        let mut cmd = CommandBuilder::new("shell");
+        cmd.env("OMPCODE", "1");
+
+        apply_pane_launch_env(&mut cmd, &PaneLaunchEnv::default());
+
+        assert!(cmd.get_env("OMPCODE").is_none());
+    }
+
+    #[test]
     fn pane_terminal_identity_removes_outer_windows_terminal_session() {
         let mut cmd = CommandBuilder::new("shell");
         cmd.env("WT_SESSION", "outer-session");