diff --git a/scripts/bump_major_version.php b/scripts/bump_major_version.php
old mode 100644
new mode 100755
diff --git a/scripts/bump_minor_version.php b/scripts/bump_minor_version.php
old mode 100644
new mode 100755
diff --git a/scripts/bump_patch_version.php b/scripts/bump_patch_version.php
old mode 100644
new mode 100755
diff --git a/tests/run.sh b/tests/run.sh
old mode 100644
new mode 100755
index 54330ba..2eb08c6
--- a/tests/run.sh
+++ b/tests/run.sh
@@ -1,4 +1,4 @@
 php -S 127.0.0.1:8000 -t PHPCurlClass/ &
-pid=$!
+pid="${!}"
 phpunit --configuration phpunit.xml
-kill $pid
+kill "${pid}"
diff --git a/tests/syntax.sh b/tests/syntax.sh
old mode 100644
new mode 100755