diff --git a/backtesting/_plotting.py b/backtesting/_plotting.py
index 0f8ae18e..3e2305b4 100644
--- a/backtesting/_plotting.py
+++ b/backtesting/_plotting.py
@@ -534,7 +534,8 @@ def __eq__(self, other):
                 if is_overlay:
                     ohlc_extreme_values[source_name] = arr
                     if is_histogram:
-                        fig.vbar('index', BAR_WIDTH, source_name, source=source, legend_label=legend_label, color=color)
+                        fig.vbar('index', BAR_WIDTH, source_name, source=source, 
+                            legend_label=legend_label, color=color)
                     elif is_scatter:
                         fig.scatter(
                             'index', source_name, source=source,
@@ -548,7 +549,8 @@ def __eq__(self, other):
                             line_width=1.3)
                 else:
                     if is_histogram:
-                        r = fig.vbar('index', BAR_WIDTH, source_name, source=source, legend_label=LegendStr(legend_label), color=color)
+                        r = fig.vbar('index', BAR_WIDTH, source_name, source=source, 
+                            legend_label=LegendStr(legend_label), color=color)
                     elif is_scatter:
                         r = fig.scatter(
                             'index', source_name, source=source,