diff --git a/src/calliope/preprocess/model_math.py b/src/calliope/preprocess/model_math.py
index 54ab6960..a05a6a12 100644
--- a/src/calliope/preprocess/model_math.py
+++ b/src/calliope/preprocess/model_math.py
@@ -63,13 +63,12 @@ def __iter__(self):
 
     def __repr__(self) -> str:
         """Custom string representation of class."""
-        return f"""
-        Calliope math definition dictionary with:
-        {len(self.data["variables"])} decision variable(s)
-        {len(self.data["global_expressions"])} global expression(s)
-        {len(self.data["constraints"])} constraint(s)
-        {len(self.data["piecewise_constraints"])} piecewise constraint(s)
-        {len(self.data["objectives"])} objective(s)
+        return f"""Calliope math definition dictionary with:
+    {len(self.data["variables"])} decision variable(s)
+    {len(self.data["global_expressions"])} global expression(s)
+    {len(self.data["constraints"])} constraint(s)
+    {len(self.data["piecewise_constraints"])} piecewise constraint(s)
+    {len(self.data["objectives"])} objective(s)
         """
 
     def add(self, math: AttrDict):