diff --git a/pybamm/expression_tree/unary_operators.py b/pybamm/expression_tree/unary_operators.py
index 3450d5cc3f..78a08181a0 100644
--- a/pybamm/expression_tree/unary_operators.py
+++ b/pybamm/expression_tree/unary_operators.py
@@ -567,10 +567,10 @@ def __init__(self, child, integration_variable):
         super().__init__(child, integration_variable)
         # Overwrite the name
         self.name = "{} integrated w.r.t {}".format(
-            child.name, integration_variable.name
+            child.name, self.integration_variable[0].name
         )
         if isinstance(integration_variable, pybamm.SpatialVariable):
-            self.name += " on {}".format(integration_variable.domain)
+            self.name += " on {}".format(self.integration_variable[0].domain)
 
 
 class BackwardIndefiniteIntegral(BaseIndefiniteIntegral):
@@ -597,10 +597,10 @@ def __init__(self, child, integration_variable):
         super().__init__(child, integration_variable)
         # Overwrite the name
         self.name = "{} integrated backward w.r.t {}".format(
-            child.name, integration_variable.name
+            child.name, self.integration_variable[0].name
         )
         if isinstance(integration_variable, pybamm.SpatialVariable):
-            self.name += " on {}".format(integration_variable.domain)
+            self.name += " on {}".format(self.integration_variable[0].domain)
 
 
 class DefiniteIntegralVector(SpatialOperator):
diff --git a/pybamm/spatial_methods/finite_volume.py b/pybamm/spatial_methods/finite_volume.py
index bba525d420..671b388c0b 100644
--- a/pybamm/spatial_methods/finite_volume.py
+++ b/pybamm/spatial_methods/finite_volume.py
@@ -342,8 +342,7 @@ def indefinite_integral_matrix_edges(self, domain, direction):
         Notes
         -----
 
-        Forward integral
-        ^^^^^^^^^^^^^^^^
+        **Forward integral**
 
         .. math::
             F(x) = \\int_0^x\\!f(u)\\,du
@@ -367,8 +366,7 @@ def indefinite_integral_matrix_edges(self, domain, direction):
         integrand vector `f`, so we add a column of zeros at each end of the
         indefinite integral matrix to ignore these.
 
-        Backward integral
-        ^^^^^^^^^^^^^^^^^
+        **Backward integral**
 
         .. math::
             F(x) = \\int_x^end\\!f(u)\\,du