diff --git a/.gitignore b/.gitignore
index 0e3b43f..5aad1db 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,9 +1,11 @@
-*vpmr*.so
-*.egg-info
+__pycache__
 .cache
 .idea/
+.venv
 .vscode/
+*.egg-info
+*vpmr*.so
 build/
 cmake-build-*/
-wheelhouse
-__pycache__
\ No newline at end of file
+venv
+wheelhouse
\ No newline at end of file
diff --git a/src/VPMR.cpp b/src/VPMR.cpp
index 406ce31..826d49c 100644
--- a/src/VPMR.cpp
+++ b/src/VPMR.cpp
@@ -462,7 +462,7 @@ PYBIND11_MODULE(_pyvpmr, m) {
 
     m.def(
         "vpmr", &vpmr_wrapper, pybind11::call_guard<pybind11::gil_scoped_release>(),
-        pybind11::kw_only(), pybind11::arg("n") = 10, pybind11::arg("d") = 0, pybind11::arg("q") = 500, pybind11::arg("m") = 1.5, pybind11::arg("nc") = 4, pybind11::arg("e") = 1E-8, pybind11::arg("k") = "",
+        pybind11::kw_only(), pybind11::arg("n") = 10, pybind11::arg("d") = 0, pybind11::arg("q") = 500, pybind11::arg("m") = 1.5, pybind11::arg("nc") = 4, pybind11::arg("e") = 1E-8, pybind11::arg("k") = "exp(-t^2/4)",
         "The VPMR Algorithm.\n\n"
         ":param n: number of terms (default: 10)\n"
         ":param d: number of precision bits (default: 512)\n"