diff --git a/.gitmodules b/.gitmodules
deleted file mode 100644
index 179f373..0000000
--- a/.gitmodules
+++ /dev/null
@@ -1,4 +0,0 @@
-[submodule "cgranges"]
-	path = cgranges
-	url = https://github.com/lh3/cgranges
-	ignore = dirty
diff --git a/build.py b/build.py
deleted file mode 100644
index e352c3e..0000000
--- a/build.py
+++ /dev/null
@@ -1,26 +0,0 @@
-from setuptools import Extension
-from Cython.Build import build_ext
-
-ext_modules = [
-    Extension(
-        "cgranges",
-        sources=["cgranges/python/cgranges.pyx", "cgranges/cgranges.c"],
-        depends=[
-            "cgranges/cgranges.h",
-            "cgranges/khash.h",
-            "cgranges/python/cgranges.pyx"
-        ],
-        include_dirs=["cgranges"]
-    )
-]
-
-def build(setup_kwargs):
-    """
-    This function is mandatory in order to build the extensions.
-    """
-    setup_kwargs.update(
-        {
-            "ext_modules": ext_modules,
-            "cmdclass": {"build_ext": build_ext},
-        }
-    )
\ No newline at end of file
diff --git a/cgranges b/cgranges
deleted file mode 160000
index 2fb5a2a..0000000
--- a/cgranges
+++ /dev/null
@@ -1 +0,0 @@
-Subproject commit 2fb5a2a8b8876b5328308dcbab5ac54200807709
diff --git a/pyproject.toml b/pyproject.toml
index 5f8e326..8ceab9b 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -44,10 +44,6 @@ pytest-cov = "^4.0.0"
 [tool.poetry.extras]
 docs = ["sphinx"]
 
-[tool.poetry.build]
-script = "build.py"
-generate-setup-file = true
-
 [build-system]
 requires = ["poetry-core", "setuptools", "cython"]
 build-backend = "poetry.core.masonry.api"