diff --git a/.coveragerc b/.coveragerc
new file mode 100644
index 0000000..e99fed0
--- /dev/null
+++ b/.coveragerc
@@ -0,0 +1,11 @@
+[run]
+branch = True
+
+[report]
+include = src/whl2conda/*
+omit = src/whl2conda/external/*
+exclude_lines =
+    pragma: no cover
+    raise AssertionError
+    raise NotImplementedError
+
diff --git a/.gitignore b/.gitignore
index e2333e6..4a0cb14 100644
--- a/.gitignore
+++ b/.gitignore
@@ -16,7 +16,8 @@ build/
 *.tar.bz2
 
 # test files
-.coverage*
+.coverage
+.coverage.*
 coverage.json
 coverage.xml
 
diff --git a/conftest.py b/conftest.py
index a959842..2162b63 100644
--- a/conftest.py
+++ b/conftest.py
@@ -41,7 +41,7 @@ def pytest_configure(config):
     Add external marker to pytest configuration
     """
     config.addinivalue_line(
-        "markers", "external: mark test as depending on extenral pypi package to run"
+        "markers", "external: mark test as depending on external pypi package to run"
     )
     config.addinivalue_line("markers", "slow: mark test as slow to run")
 
diff --git a/pyproject.toml b/pyproject.toml
index ea56d02..582c40e 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -55,6 +55,21 @@ pattern = "\\s*(?P<version>[\\w.]*)"
 [tool.hatch.build.targets.wheel]
 packages = ["src/whl2conda"]
 
+# TODO: Using coverage config in pyproject is resulting in
+#    INTERNALERROR> coverage.exceptions.DataError: Can't combine line data with arc data
+#
+#[tool.coverage.run]
+#branch = true
+#
+#[tool.coverage.report]
+#include = ["src/whl2conda/*"]
+#omit = ["src/whl2conda/external/*"]
+#exclude_also = [
+#    "pragma: no cover",
+#    "raise AssertionError",
+#    "raise NotImplementedError"
+#]
+
 [tool.black]
 line-length = 88
 skip-string-normalization = true