diff --git a/buildingmotif/dataclasses/validation.py b/buildingmotif/dataclasses/validation.py
index e7e53868..c73dba96 100644
--- a/buildingmotif/dataclasses/validation.py
+++ b/buildingmotif/dataclasses/validation.py
@@ -187,7 +187,9 @@ def from_validation_report(cls, report: Graph) -> List["PathClassCount"]:
     def reason(self) -> str:
         """Human-readable explanation of this GraphDiff."""
         # interpret a SHACL property path as a sparql property path
-        path = shacl_path_to_sparql_path(self.graph, self.path, prefixes=dict(self.graph.namespaces()))
+        path = shacl_path_to_sparql_path(
+            self.graph, self.path, prefixes=dict(self.graph.namespaces())
+        )
 
         classname = self.graph.qname(self.classname)
         if self.maxc is None and self.minc is not None:
@@ -377,7 +379,9 @@ def from_validation_report(cls, report: Graph) -> List["RequiredPath"]:
 
     def reason(self) -> str:
         """Human-readable explanation of this GraphDiff."""
-        path = shacl_path_to_sparql_path(self.graph, self.path, prefixes=dict(self.graph.namespaces()))
+        path = shacl_path_to_sparql_path(
+            self.graph, self.path, prefixes=dict(self.graph.namespaces())
+        )
         if self.maxc is None and self.minc is not None:
             return f"{self.focus} needs at least {self.minc} uses of path {path}"
         if self.minc is None and self.maxc is not None: