diff --git a/setup/so-variables b/setup/so-variables
index 1123562d9..07f7aa71b 100644
--- a/setup/so-variables
+++ b/setup/so-variables
@@ -28,7 +28,7 @@ mkdir -p /nsm
 filesystem_nsm=$(df /nsm | awk '$3 ~ /[0-9]+/ { print $2 * 1000 }')
 export filesystem_nsm
 
-free_space_root=$(df -Pk / | sed 1d | grep -v used | awk '{ print $4 / 1048576 }' | awk '{ printf("%.0f", $1) }')
+free_space_root=$(df -Pk /nsm | sed 1d | grep -v used | awk '{ print $4 / 1048576 }' | awk '{ printf("%.0f", $1) }')
 export free_space_root
 
 mkdir -p /root/installtmp/pillar/minions