diff --git a/git-submodule.sh b/git-submodule.sh
index b5f2bee..470f681 100755
--- a/git-submodule.sh
+++ b/git-submodule.sh
@@ -10,6 +10,7 @@
    or: $dashless [--quiet] init [--] [<path>...]
    or: $dashless [--quiet] deinit [-f|--force] (--all| [--] <path>...)
    or: $dashless [--quiet] update [--init] [--remote] [-N|--no-fetch] [-f|--force] [--checkout|--merge|--rebase] [--[no-]recommend-shallow] [--reference <repository>] [--recursive] [--] [<path>...]
+   or: $dashless [--quiet] set-branch (--default|--branch <branch>) [--] <path>
    or: $dashless [--quiet] summary [--cached|--files] [--summary-limit <n>] [commit] [--] [<path>...]
    or: $dashless [--quiet] foreach [--recursive] <command>
    or: $dashless [--quiet] sync [--recursive] [--] [<path>...]
@@ -685,6 +686,72 @@
 }
 
 #
+# Configures a submodule's default branch
+#
+# $@ = requested path
+#
+cmd_set_branch() {
+	unset_branch=false
+	branch=
+
+	while test $# -ne 0
+	do
+		case "$1" in
+		-q|--quiet)
+			# we don't do anything with this but we need to accept it
+			;;
+		-d|--default)
+			unset_branch=true
+			;;
+		-b|--branch)
+			case "$2" in '') usage ;; esac
+			branch=$2
+			shift
+			;;
+		--)
+			shift
+			break
+			;;
+		-*)
+			usage
+			;;
+		*)
+			break
+			;;
+		esac
+		shift
+	done
+
+	if test $# -ne 1
+	then
+		usage
+	fi
+
+	# we can't use `git submodule--helper name` here because internally, it
+	# hashes the path so a trailing slash could lead to an unintentional no match
+	name="$(git submodule--helper list "$1" | cut -f2)"
+	if test -z "$name"
+	then
+		exit 1
+	fi
+
+	test -n "$branch"; has_branch=$?
+	test "$unset_branch" = true; has_unset_branch=$?
+
+	if test $((!$has_branch != !$has_unset_branch)) -eq 0
+	then
+		usage
+	fi
+
+	if test $has_branch -eq 0
+	then
+		git submodule--helper config submodule."$name".branch "$branch"
+	else
+		git submodule--helper config --unset submodule."$name".branch
+	fi
+}
+
+#
 # Show commit summary for submodules in index or working tree
 #
 # If '--cached' is given, show summary between index and given commit,
@@ -983,7 +1050,7 @@
 while test $# != 0 && test -z "$command"
 do
 	case "$1" in
-	add | foreach | init | deinit | update | status | summary | sync | absorbgitdirs)
+	add | foreach | init | deinit | update | set-branch | status | summary | sync | absorbgitdirs)
 		command=$1
 		;;
 	-q|--quiet)
@@ -1024,8 +1091,8 @@
     fi
 fi
 
-# "-b branch" is accepted only by "add"
-if test -n "$branch" && test "$command" != add
+# "-b branch" is accepted only by "add" and "set-branch"
+if test -n "$branch" && (test "$command" != add || test "$command" != set-branch)
 then
 	usage
 fi
@@ -1036,4 +1103,4 @@
 	usage
 fi
 
-"cmd_$command" "$@"
+"cmd_$(echo $command | sed -e s/-/_/g)" "$@"