diff --git a/bob/bio/base/script/commands.py b/bob/bio/base/script/commands.py
index c6e015854242d0f7806713a90668f9ce93bf4459..20cfffa5d512826cc34e4da931b5d0ad73d3bc58 100644
--- a/bob/bio/base/script/commands.py
+++ b/bob/bio/base/script/commands.py
@@ -148,7 +148,7 @@ def det(ctx, scores, evaluation, **kargs):
     process.run()
 
 @click.command()
-@common_options.scores_argument(min_arg=2, nargs=-1)
+@common_options.scores_argument(min_arg=1, force_eval=True, nargs=-1)
 @common_options.output_plot_file_option(default_out='epc.pdf')
 @common_options.titles_option()
 @common_options.points_curve_option()