diff --git a/pyproject.toml b/pyproject.toml
index 8e6e44f..9930065 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -26,6 +26,9 @@ testing = [
     "mypy",
     "lxml",  # for mypy html coverage
 ]
+zstd = [
+    "zstandard",
+]
 
 
 [build-system]
diff --git a/src/kompress/__init__.py b/src/kompress/__init__.py
index 296a098..cd2d665 100644
--- a/src/kompress/__init__.py
+++ b/src/kompress/__init__.py
@@ -43,10 +43,10 @@ def is_compressed(p: PathIsh) -> bool:
 
 
 def _zstd_open(path: Path, *args, **kwargs) -> IO:
-    import zstandard as zstd  # type: ignore
+    import zstandard
 
     fh = path.open('rb')
-    dctx = zstd.ZstdDecompressor()
+    dctx = zstandard.ZstdDecompressor()
     reader = dctx.stream_reader(fh)
 
     mode = kwargs.get('mode', 'rt')
diff --git a/tox.ini b/tox.ini
index f71168c..5a7d990 100644
--- a/tox.ini
+++ b/tox.ini
@@ -38,7 +38,7 @@ commands =
 
 [testenv:mypy]
 commands =
-    {envpython} -m pip install --use-pep517 -e .[testing]
+    {envpython} -m pip install --use-pep517 -e .[testing,zstd]
     {envpython} -m mypy --install-types --non-interactive \
         -p {[testenv]package_name}       \
         # txt report is a bit more convenient to view on CI