diff --git a/changes.md b/changes.md
index aec0723a..b2f875cb 100644
--- a/changes.md
+++ b/changes.md
@@ -1,5 +1,8 @@
 # Changes
 
+## 0.1.13
+- fixed bug when no predecessor model is provided, introduced in 0.1.11 (#83)
+
 ## 0.1.12
 - fixed bug in last version: non-FAMoS methods do not terminate
 
diff --git a/petab_select/ui.py b/petab_select/ui.py
index 4050d4c2..204ffd35 100644
--- a/petab_select/ui.py
+++ b/petab_select/ui.py
@@ -94,7 +94,10 @@ def candidates(
     predecessor_model = candidate_space.previous_predecessor_model
 
     # If the predecessor model has not yet been calibrated, then calibrate it.
-    if predecessor_model != VIRTUAL_INITIAL_MODEL:
+    if (
+        predecessor_model is not None
+        and predecessor_model != VIRTUAL_INITIAL_MODEL
+    ):
         if (
             predecessor_model.get_criterion(
                 criterion,
diff --git a/petab_select/version.py b/petab_select/version.py
index 22f32c72..6312a57b 100644
--- a/petab_select/version.py
+++ b/petab_select/version.py
@@ -1,2 +1,2 @@
 """Version of the model selection extension for PEtab."""
-__version__ = '0.1.12'
+__version__ = '0.1.13'