diff --git a/doc/source/conf.py b/doc/source/conf.py
old mode 100755
new mode 100644
diff --git a/tools/find_executables.sh b/tools/find_executables.sh
new file mode 100644
index 0000000..a0700cd
--- /dev/null
+++ b/tools/find_executables.sh
@@ -0,0 +1,11 @@
+OUTPUT=`find . \( -name .tox -o -name .git \) -prune -o -type f -perm /a=x -print`
+if [ -n "$OUTPUT" ]; then
+    echo "Unexpected executable files are found:"
+    for f in $OUTPUT; do
+        echo $f
+    done
+    echo
+    echo "If you really need to add an executable file, add it to tools/executable_files.txt"
+    exit 1
+fi
+
diff --git a/tox.ini b/tox.ini
index 276d13e..f26af55 100644
--- a/tox.ini
+++ b/tox.ini
@@ -14,7 +14,12 @@ commands = /bin/rm -f .testrepository/times.dbm
 
 [testenv:pep8]
 basepython = python3
-commands = flake8
+whitelist_externals =
+  bash
+  find
+commands =
+  flake8
+  bash {toxinidir}/tools/find_executables.sh
 
 [testenv:npm]
 basepython = python3
diff --git a/vitrage_dashboard/alarms/templates/alarms/banner.html b/vitrage_dashboard/alarms/templates/alarms/banner.html
old mode 100755
new mode 100644
diff --git a/vitrage_dashboard/alarms/views.py b/vitrage_dashboard/alarms/views.py
old mode 100755
new mode 100644
diff --git a/vitrage_dashboard/dashboard/static/dashboard/project/components/alarms/alarms.scss b/vitrage_dashboard/dashboard/static/dashboard/project/components/alarms/alarms.scss
old mode 100755
new mode 100644
diff --git a/vitrage_dashboard/dashboard/static/dashboard/project/vitrage.scss b/vitrage_dashboard/dashboard/static/dashboard/project/vitrage.scss
old mode 100755
new mode 100644
diff --git a/vitrage_dashboard/enabled/_4020_project_alarms_vitrage_panel.py b/vitrage_dashboard/enabled/_4020_project_alarms_vitrage_panel.py
old mode 100755
new mode 100644