diff --git a/test/pyenv_ext.bats b/test/pyenv_ext.bats
index cc138cbe..fdae87fc 100644
--- a/test/pyenv_ext.bats
+++ b/test/pyenv_ext.bats
@@ -12,3 +12,19 @@ load test_helper
   PYENV_VERSION="2.7.10:system" run pyenv-prefix
   assert_success "${PYENV_ROOT}/versions/2.7.10:${PYENV_TEST_DIR}"
 }
+
+@test "should use dirname of file argument as PYENV_DIR" {
+  mkdir -p "${PYENV_TEST_DIR}/dir1"
+  touch "${PYENV_TEST_DIR}/dir1/file.py"
+  PYENV_FILE_ARG="${PYENV_TEST_DIR}/dir1/file.py" run pyenv echo PYENV_DIR
+  assert_output "${PYENV_TEST_DIR}/dir1"
+}
+
+@test "should follow symlink of file argument (#379, #404)" {
+  mkdir -p "${PYENV_TEST_DIR}/dir1"
+  mkdir -p "${PYENV_TEST_DIR}/dir2"
+  touch "${PYENV_TEST_DIR}/dir1/file.py"
+  ln -s "${PYENV_TEST_DIR}/dir1/file.py" "${PYENV_TEST_DIR}/dir2/symlink.py"
+  PYENV_FILE_ARG="${PYENV_TEST_DIR}/dir2/symlink.py" run pyenv echo PYENV_DIR
+  assert_output "${PYENV_TEST_DIR}/dir1"
+}