diff --git a/arigram/models.py b/arigram/models.py
index 4b4986f..e3efef5 100644
--- a/arigram/models.py
+++ b/arigram/models.py
@@ -225,7 +225,7 @@ class Model:
         self.copied_msgs = (0, [])
         return True
 
-    def get_current_message_text(self) -> tuple[str, bool]:
+    def get_current_message_text(self) -> Tuple[str, bool]:
         buffer = []
 
         from_chat_id, msg_ids = self.copied_msgs
diff --git a/check.sh b/check.sh
index c4418c3..d124056 100755
--- a/check.sh
+++ b/check.sh
@@ -12,7 +12,8 @@ mypy arigram --warn-redundant-casts --warn-unused-ignores \
     --disallow-untyped-calls --disallow-untyped-defs \
     --disallow-incomplete-defs --check-untyped-defs \
     --disallow-untyped-decorators --pretty --show-traceback \
-    --no-warn-unused-ignores --follow-imports=error --namespace-packages
+    --no-warn-unused-ignores --follow-imports=error --namespace-packages \
+    --python-version "$(head -n1 runtime.txt)"
 
 echo Checking import sorting...
 isort -c arigram/*.py
diff --git a/runtime.txt b/runtime.txt
new file mode 100644
index 0000000..cc1923a
--- /dev/null
+++ b/runtime.txt
@@ -0,0 +1 @@
+3.8