1 files changed, 2 insertions, 1 deletions

diff --git a/git-submodule.sh b/git-submodule.sh
index 383dc45119..9aa57dd6f7 100755
--- a/git-submodule.sh
+++ b/git-submodule.sh
@@ -559,7 +559,8 @@ cmd_summary() {
 		test $# = 0 || shift
 	elif test -z "$1" -o "$1" = "HEAD"
 	then
-		return
+		# before the first commit: compare with an empty tree
+		head=$(git hash-object -w -t tree --stdin </dev/null)
 	else
 		head="HEAD"
 	fi