diff --git a/getssl b/getssl
index 8e459c3..c5e4395 100755
--- a/getssl
+++ b/getssl
@@ -75,7 +75,7 @@ _FORCE_RENEW=0
 _QUIET=0
 
 clean_up() { # Perform pre-exit housekeeping
-  umask=$ORIG_UMASK
+  umask "$ORIG_UMASK"
   if [ ! -z "$DOMAIN_DIR" ]; then
     rm -rf "${TEMP_DIR:?}"
   fi