diff --git a/returnn/tensor/_dim_extra.py b/returnn/tensor/_dim_extra.py
index 4635e79fc9..74dc18472f 100644
--- a/returnn/tensor/_dim_extra.py
+++ b/returnn/tensor/_dim_extra.py
@@ -1184,6 +1184,8 @@ def _bin_op_tf(a, b):
             elif kind in ("floordiv", "truediv"):  # truediv assumes there is no remainder
                 return a // b
             elif kind == "ceildiv":
+                if util.is_onnx_export_global():
+                    return -tf_util.onnx_compat_floor_div(-a, b)
                 return -(-a // b)
             else:
                 raise ValueError("unknown op kind %r" % op.kind)