diff --git a/git-submodule.sh b/git-submodule.sh
index 1c1dc32..7fc7119 100755
--- a/git-submodule.sh
+++ b/git-submodule.sh
@@ -40,7 +40,9 @@
 files=
 remote=
 nofetch=
-update=
+rebase=
+merge=
+checkout=
 custom_name=
 depth=
 progress=
@@ -260,7 +262,7 @@
 			force=$1
 			;;
 		-r|--rebase)
-			update="rebase"
+			rebase=1
 			;;
 		--reference)
 			case "$2" in '') usage ;; esac
@@ -274,13 +276,13 @@
 			dissociate=1
 			;;
 		-m|--merge)
-			update="merge"
+			merge=1
 			;;
 		--recursive)
 			recursive=1
 			;;
 		--checkout)
-			update="checkout"
+			checkout=1
 			;;
 		--recommend-shallow)
 			recommend_shallow="--recommend-shallow"
@@ -341,7 +343,9 @@
 		${init:+--init} \
 		${nofetch:+--no-fetch} \
 		${wt_prefix:+--prefix "$wt_prefix"} \
-		${update:+--update "$update"} \
+		${rebase:+--rebase} \
+		${merge:+--merge} \
+		${checkout:+--checkout} \
 		${reference:+"$reference"} \
 		${dissociate:+"--dissociate"} \
 		${depth:+"$depth"} \