diff --git a/doc/whatsnew/fragments/8161.bugfix b/doc/whatsnew/fragments/8161.bugfix
new file mode 100644
index 0000000000..9570991809
--- /dev/null
+++ b/doc/whatsnew/fragments/8161.bugfix
@@ -0,0 +1,3 @@
+Fix a crash happening for python interpreter < 3.9 following a failed typing update.
+
+Closes #8161
diff --git a/pylint/checkers/imports.py b/pylint/checkers/imports.py
index a66400441a..d29056b8c2 100644
--- a/pylint/checkers/imports.py
+++ b/pylint/checkers/imports.py
@@ -176,7 +176,7 @@ def _make_tree_defs(mod_files_list: ItemsView[str, set[str]]) -> _ImportTree:
             assert isinstance(node[0], dict)
             node = node[0].setdefault(prefix, ({}, []))  # type: ignore[arg-type,assignment]
         assert isinstance(node[1], list)
-        node[1] += files
+        node[1].extend(files)
     return tree_defs