diff --git a/bmi_tester/_version.py b/bmi_tester/_version.py
index 1cc82e6..ab4bb7e 100644
--- a/bmi_tester/_version.py
+++ b/bmi_tester/_version.py
@@ -1 +1 @@
-__version__ = "0.5.7"
+__version__ = "0.5.8.dev0"