diff --git a/astronaut/astronaut b/astronaut/astronaut
index 95403a8..b349803 100755
--- a/astronaut/astronaut
+++ b/astronaut/astronaut
@@ -171,7 +171,8 @@ download() {
         [ "$4" ] && local cmd="$4" || local cmd="$cmd_download"
         eval $(echo "$cmd" | sed -e "s/{dst}/'$(safe_sed "$path")'/g" -e "s/{src}/'$(safe_sed "$1")'/g")
 
-        if [ "$2" -a "$(_mksum "$path")" != "$2" ]; then
+        local checksum="$(_mksum "$path")"
+        if [ "$2" -a "$checksum" != "$2" ]; then
             _msg "Checksum: $checksum"
             _exiterr 'Checksum failed'
         fi