diff --git a/python/sglang/srt/model_executor/runner_backend/breakable_cuda_graph_backend.py b/python/sglang/srt/model_executor/runner_backend/breakable_cuda_graph_backend.py
index 368db2ebc719..83646155cac7 100644
--- a/python/sglang/srt/model_executor/runner_backend/breakable_cuda_graph_backend.py
+++ b/python/sglang/srt/model_executor/runner_backend/breakable_cuda_graph_backend.py
@@ -124,6 +124,12 @@ def capture_one(
             if post_warmup_hook is not None:
                 post_warmup_hook()
 
+        # The syncs above order work issued before each warmup, not the last
+        # warmup's own. A JIT module that finishes loading mid-capture issues
+        # illegal driver calls on the capturing stream, so drain once more here.
+        self._device_module.synchronize()
+        self._tp_group.barrier()
+
         graph = BreakableCUDAGraph(self.deduped_cuda_graph)
         captured_fn = (
             eager_on_graph(True)(forward_fn) if self._debug_eager else forward_fn
diff --git a/python/sglang/srt/model_executor/runner_backend/full_cuda_graph_backend.py b/python/sglang/srt/model_executor/runner_backend/full_cuda_graph_backend.py
index 3a047c8ffa64..508ab1b840d6 100644
--- a/python/sglang/srt/model_executor/runner_backend/full_cuda_graph_backend.py
+++ b/python/sglang/srt/model_executor/runner_backend/full_cuda_graph_backend.py
@@ -157,6 +157,12 @@ def capture_one(
             self._reuse_output_buffer = self._output_buffer is not None
         del warmup_output
 
+        # The syncs above order work issued before each warmup, not the last
+        # warmup's own. A JIT module that finishes loading mid-capture issues
+        # illegal driver calls on the capturing stream, so drain once more here.
+        self._device_module.synchronize()
+        self._tp_group.barrier()
+
         graph = torch.cuda.CUDAGraph()
 
         graph_ctx: Callable[..., AbstractContextManager]