diff --git a/pcmdi_metrics/graphics/portrait_plot/portrait_plot_lib.py b/pcmdi_metrics/graphics/portrait_plot/portrait_plot_lib.py
index f791ab99d..8209bdfbd 100644
--- a/pcmdi_metrics/graphics/portrait_plot/portrait_plot_lib.py
+++ b/pcmdi_metrics/graphics/portrait_plot/portrait_plot_lib.py
@@ -505,7 +505,7 @@ def annotate_heatmap(
                 kw.update(color=textcolors[int(data[i, j] > threshold)])
             text = ax.text(j + 0.5, i + 0.5, valfmt(annotate_data[i, j], None), **kw)
             texts.append(text)
-            
+
     return ax