diff --git a/t/Dockerfile b/t/Dockerfile
index fb96878..d8eabad 100644
--- a/t/Dockerfile
+++ b/t/Dockerfile
@@ -30,6 +30,11 @@ RUN apt-get clean
 
 RUN echo "cd /code && ./t/testrunner 1.2.3.4" > /root/.bash_history
 
+# Create files with mode 666 and folders with mode 777 which
+# allows to delete the temporary files (aka results) for
+# non-root users (like 'jenkins' or 'developer's laptop local user')
+RUN echo 'umask 0' >>/root/.bashrc
+
 WORKDIR /code
 
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