diff --git a/packages/python/plotly/plotly/express/_core.py b/packages/python/plotly/plotly/express/_core.py
index f92d86a357b..21c0ca03cc1 100644
--- a/packages/python/plotly/plotly/express/_core.py
+++ b/packages/python/plotly/plotly/express/_core.py
@@ -236,7 +236,7 @@ def make_trace_kwargs(args, trace_spec, g, mapping_labels, sizeref):
fit_results = sm.OLS(y.values, sm.add_constant(x.values)).fit()
result["y"] = fit_results.predict()
hover_header = "OLS trendline
"
- hover_header += "%s = %f * %s + %f
" % (
+ hover_header += "%s = %g * %s + %g
" % (
args["y"],
fit_results.params[1],
args["x"],