diff --git a/run/run.sh b/run/run.sh
index f6e43a2..c7cf6d1 100755
--- a/run/run.sh
+++ b/run/run.sh
@@ -44,4 +44,4 @@ set -m
 set +m
 
 # Wait for QEMU process to exit
-tail --pid=$(cat ${_QEMU_PID}) -f /dev/null
+tail --pid=$(cat "${_QEMU_PID}") -f /dev/null