diff --git a/mbtrack2/instability/__init__.py b/mbtrack2/instability/__init__.py
index 6d59c921aa754f11e2d190f8b1a3bda1f0bf1625..0fa6890eaf6414376c93057ec156b3a513fc360b 100644
--- a/mbtrack2/instability/__init__.py
+++ b/mbtrack2/instability/__init__.py
@@ -15,4 +15,5 @@ from mbtrack2.instability.ions import (
     plot_critical_mass,
 )
 from mbtrack2.instability.space_charge import (
-    transverse_space_charge_tune_shift, )
+    transverse_space_charge_tune_shift,
+)