diff --git a/requirements.txt b/requirements.txt
index 5633c9b..2986c69 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,4 +1,4 @@
 pydicom
 numpy
 opencv-python>=4.0.0
-dataclasses
\ No newline at end of file
+dataclasses ; python_version <= "3.6"
\ No newline at end of file