diff --git a/sh/main.sh b/sh/main.sh
index 6369d05..fa0c556 100644
--- a/sh/main.sh
+++ b/sh/main.sh
@@ -1,5 +1,5 @@
 SH_NAME="sh"
-SH_SHELL="$(cat /proc/$$/comm)"
+SH_SHELL="$(cat /proc/${$}/comm)"
 export SH_SHELL
 
 SH_ROOT="/etc/${SH_NAME}"