diff --git a/codex-rs/core/src/tasks/mod.rs b/codex-rs/core/src/tasks/mod.rs
index b2f110486c..b91e28319b 100644
--- a/codex-rs/core/src/tasks/mod.rs
+++ b/codex-rs/core/src/tasks/mod.rs
@@ -186,11 +186,12 @@ impl Session {
             let ctx = Arc::clone(&turn_context);
             let task_for_run = Arc::clone(&task);
             let task_cancellation_token = cancellation_token.child_token();
-            // Task-owned turn spans keep a core-owned span open for the
-            // full task lifecycle after the submission dispatch span ends.
+            // Task-owned turn spans keep a core-owned parent span open for the
+            // full turn lifecycle after the submission dispatch span ends.
             let task_span = info_span!(
                 "turn",
                 otel.name = span_name,
+                conversation.id = %self.conversation_id,
                 thread.id = %self.conversation_id,
                 turn.id = %turn_context.sub_id,
                 model = %turn_context.model_info.slug,
diff --git a/codex-rs/core/tests/suite/otel.rs b/codex-rs/core/tests/suite/otel.rs
index 4fadee0770..08b90c5bf1 100644
--- a/codex-rs/core/tests/suite/otel.rs
+++ b/codex-rs/core/tests/suite/otel.rs
@@ -747,7 +747,12 @@ async fn responses_request_span_records_turn_correlation_fields() {
         lines
             .iter()
             .find(|line| {
-                line.contains("responses_http.request{")
+                line.contains("turn{otel.name=\"session_task.turn\"")
+                    && line.contains("conversation.id=")
+                    && line.contains("thread.id=")
+                    && line.contains("turn.id=")
+                    && line.contains("model=")
+                    && line.contains("responses_http.request{")
                     && line.contains("otel.kind=\"client\"")
                     && line.contains("transport=\"responses_http\"")
                     && line.contains("conversation.id=")
@@ -756,7 +761,10 @@ async fn responses_request_span_records_turn_correlation_fields() {
             })
             .map(|_| Ok(()))
             .unwrap_or_else(|| {
-                Err("missing responses_http.request span with correlation fields".to_string())
+                Err(
+                    "missing responses_http.request span nested under session_task.turn"
+                        .to_string(),
+                )
             })
     });
 }
diff --git a/codex-rs/core/tests/suite/rmcp_client.rs b/codex-rs/core/tests/suite/rmcp_client.rs
index 337d4d69b3..0f31222923 100644
--- a/codex-rs/core/tests/suite/rmcp_client.rs
+++ b/codex-rs/core/tests/suite/rmcp_client.rs
@@ -194,7 +194,12 @@ async fn stdio_server_round_trip() -> anyhow::Result<()> {
         lines
             .iter()
             .find(|line| {
-                line.contains("mcp.tools.call{")
+                line.contains("turn{otel.name=\"session_task.turn\"")
+                    && line.contains("conversation.id=")
+                    && line.contains("thread.id=")
+                    && line.contains("turn.id=")
+                    && line.contains("model=")
+                    && line.contains("mcp.tools.call{")
                     && line.contains("otel.kind=\"client\"")
                     && line.contains("rpc.system=\"jsonrpc\"")
                     && line.contains("rpc.method=\"tools/call\"")
@@ -205,7 +210,9 @@ async fn stdio_server_round_trip() -> anyhow::Result<()> {
                     && line.contains("turn.id=")
             })
             .map(|_| Ok(()))
-            .unwrap_or_else(|| Err("missing mcp.tools.call span with MCP fields".to_string()))
+            .unwrap_or_else(|| {
+                Err("missing mcp.tools.call span nested under session_task.turn".to_string())
+            })
     });
 
     server.verify().await;