diff --git a/GPy/plotting/plotly_dep/defaults.py b/GPy/plotting/plotly_dep/defaults.py
index 121e0b37..c5b2540c 100644
--- a/GPy/plotting/plotly_dep/defaults.py
+++ b/GPy/plotting/plotly_dep/defaults.py
@@ -44,7 +44,7 @@ it gives back an empty default, when defaults are not defined.
 
 # Data plots:
 data_1d = dict(marker_kwargs=dict(), marker='x', color='black')
-data_2d = dict(marker='o', cmap='Hot', marker_kwargs=dict(opacity=1., size='5', line=Line(width=.5, color='black')))
+data_2d = dict(marker='o', cmap='Hot', marker_kwargs=dict(opacity=1., size=5, line=Line(width=.5, color='black')))
 inducing_1d = dict(color=Tango.colorsHex['darkRed'])
 inducing_2d = dict(marker_kwargs=dict(size='5', opacity=.7, line=Line(width=.5, color='black')), opacity=.7, color='white', marker='star-triangle-up')
 inducing_3d = dict(marker_kwargs=dict(symbol='diamond', size='5', opacity=.7, line=Line(width=.1, color='black')), color='#F5F5F5')