diff --git a/git-stash.sh b/git-stash.sh
index d4cf818be9..cc28368b01 100755
--- a/git-stash.sh
+++ b/git-stash.sh
@@ -442,6 +442,8 @@ apply_stash () {
 	assert_stash_like "$@"
 
 	git update-index -q --refresh || die "$(gettext "unable to refresh index")"
+	git diff-index --cached --quiet --ignore-submodules HEAD -- ||
+		die "$(gettext "Cannot apply stash: Your index contains uncommitted changes.")"
 
 	# current index state
 	c_tree=$(git write-tree) ||
diff --git a/t/t3903-stash.sh b/t/t3903-stash.sh
index f179c93ddf..0746eeeff7 100755
--- a/t/t3903-stash.sh
+++ b/t/t3903-stash.sh
@@ -45,6 +45,13 @@ test_expect_success 'applying bogus stash does nothing' '
 	test_cmp expect file
 '
 
+test_expect_success 'apply requires a clean index' '
+	test_when_finished "git reset --hard" &&
+	echo changed >other-file &&
+	git add other-file &&
+	test_must_fail git stash apply
+'
+
 test_expect_success 'apply does not need clean working directory' '
 	echo 4 >other-file &&
 	git stash apply &&