diff --git a/src/gouge/colourcli.py b/src/gouge/colourcli.py
index 3ede7c9..0929b1d 100644
--- a/src/gouge/colourcli.py
+++ b/src/gouge/colourcli.py
@@ -170,8 +170,8 @@ def format(self, record: LogRecord) -> str:
 
     def formatException(self, exc_info: tuple) -> str:
         exc_text = super().formatException(exc_info)
-        if '{' in exc_text or '}' in exc_text:
-            exc_text = exc_text.replace('{', '{{').replace('}', '}}')
+        if "{" in exc_text or "}" in exc_text:
+            exc_text = exc_text.replace("{", "{{").replace("}", "}}")
         if self.highlighted_path is None:
             return exc_text