diff --git a/tests/python/modules/render_report.py b/tests/python/modules/render_report.py
index 20376c780dc..4bcf45b4fa8 100755
--- a/tests/python/modules/render_report.py
+++ b/tests/python/modules/render_report.py
@@ -429,7 +429,7 @@ class Report:
             "-o", diff_color_img,
         )
         try:
-            subprocess.check_output(command)
+            subprocess.check_output(command, stderr=subprocess.STDOUT)
         except subprocess.CalledProcessError as e:
             if self.verbose:
                 print_message(e.output.decode("utf-8", 'ignore'))
@@ -447,7 +447,7 @@ class Report:
             "-o", diff_alpha_img,
         )
         try:
-            subprocess.check_output(command)
+            subprocess.check_output(command, stderr=subprocess.STDOUT)
         except subprocess.CalledProcessError as e:
             if self.verbose:
                 msg = e.output.decode("utf-8", 'ignore')