diff --git a/bmcs_course/1_1_elastic_stiffness_of_the_composite.ipynb b/bmcs_course/1_1_elastic_stiffness_of_the_composite.ipynb
index 8c23489eb65bbbb8796eb0ac4a75d53b6a1b306e..eacb186ebd8f839d198c6fa739b93475f9e55257 100644
--- a/bmcs_course/1_1_elastic_stiffness_of_the_composite.ipynb
+++ b/bmcs_course/1_1_elastic_stiffness_of_the_composite.ipynb
@@ -370,7 +370,7 @@
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    "pygments_lexer": "ipython3",
-   "version": "3.9.1"
+   "version": "3.8.8"
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