diff --git a/t/t1501-worktree.sh b/t/t1501-worktree.sh
new file mode 100755
index 0000000000..aadeeab9ab
--- /dev/null
+++ b/t/t1501-worktree.sh
@@ -0,0 +1,92 @@
+#!/bin/sh
+
+test_description='test separate work tree'
+. ./test-lib.sh
+
+test_rev_parse() {
+	name=$1
+	shift
+
+	test_expect_success "$name: is-bare-repository" \
+	"test '$1' = \"\$(git rev-parse --is-bare-repository)\""
+	shift
+	[ $# -eq 0 ] && return
+
+	test_expect_success "$name: is-inside-git-dir" \
+	"test '$1' = \"\$(git rev-parse --is-inside-git-dir)\""
+	shift
+	[ $# -eq 0 ] && return
+
+	test_expect_success "$name: is-inside-work-tree" \
+	"test '$1' = \"\$(git rev-parse --is-inside-work-tree)\""
+	shift
+	[ $# -eq 0 ] && return
+
+	test_expect_success "$name: prefix" \
+	"test '$1' = \"\$(git rev-parse --show-prefix)\""
+	shift
+	[ $# -eq 0 ] && return
+}
+
+mkdir -p work/sub/dir || exit 1
+mv .git repo.git || exit 1
+
+say "core.worktree = relative path"
+export GIT_DIR=repo.git
+export GIT_CONFIG=$GIT_DIR/config
+unset GIT_WORK_TREE
+git config core.worktree ../work
+test_rev_parse 'outside'      false false false
+cd work || exit 1
+export GIT_DIR=../repo.git
+export GIT_CONFIG=$GIT_DIR/config
+test_rev_parse 'inside'       false false true ''
+cd sub/dir || exit 1
+export GIT_DIR=../../../repo.git
+export GIT_CONFIG=$GIT_DIR/config
+test_rev_parse 'subdirectory' false false true sub/dir/
+cd ../../.. || exit 1
+
+say "core.worktree = absolute path"
+export GIT_DIR=$(pwd)/repo.git
+export GIT_CONFIG=$GIT_DIR/config
+git config core.worktree "$(pwd)/work"
+test_rev_parse 'outside'      false false false
+cd work || exit 1
+test_rev_parse 'inside'       false false true ''
+cd sub/dir || exit 1
+test_rev_parse 'subdirectory' false false true sub/dir/
+cd ../../.. || exit 1
+
+say "GIT_WORK_TREE=relative path (override core.worktree)"
+export GIT_DIR=$(pwd)/repo.git
+export GIT_CONFIG=$GIT_DIR/config
+git config core.worktree non-existent
+export GIT_WORK_TREE=work
+test_rev_parse 'outside'      false false false
+cd work || exit 1
+export GIT_WORK_TREE=.
+test_rev_parse 'inside'       false false true ''
+cd sub/dir || exit 1
+export GIT_WORK_TREE=../..
+test_rev_parse 'subdirectory' false false true sub/dir/
+cd ../../.. || exit 1
+
+mv work repo.git/work
+
+say "GIT_WORK_TREE=absolute path, work tree below git dir"
+export GIT_DIR=$(pwd)/repo.git
+export GIT_CONFIG=$GIT_DIR/config
+export GIT_WORK_TREE=$(pwd)/repo.git/work
+test_rev_parse 'outside'              false false false
+cd repo.git || exit 1
+test_rev_parse 'in repo.git'              false true  false
+cd objects || exit 1
+test_rev_parse 'in repo.git/objects'      false true  false
+cd ../work || exit 1
+test_rev_parse 'in repo.git/work'         false false true ''
+cd sub/dir || exit 1
+test_rev_parse 'in repo.git/sub/dir' false false true sub/dir/
+cd ../../../.. || exit 1
+
+test_done