Add edges to colorbar in seaborn heatmap

I have the following heatmap:

import seaborn as sns
import matplotlib.pyplot as plt
import numpy as np

# Create a sample heatmap
data = np.random.rand(10, 12)
ax = sns.heatmap(data)


plt.show()

How can I add a black edge to the colormap? Is there any way to do this without needing to use subplots?

Looks like seaborn turns the edges off by default.

Here's an approach to get a reference to the colorbar Axes, and then re-apply the edge:

ax = sns.heatmap(data)

cax = ax.figure.get_children()[-1]
cax.spines['outline'].set_linewidth(0.5) # adjust as desired

Output: