diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
index 84f60fc4..152be3a2 100644
--- a/.github/workflows/tests.yml
+++ b/.github/workflows/tests.yml
@@ -36,31 +36,31 @@ jobs:
 
     - name: Run tests
       run: |
-        poetry run coverage run --source=opshin -m pytest opshin/tests
-        poetry run coverage run -a --source=opshin -m opshin eval spending examples/smart_contracts/assert_sum.py "{\"int\": 4}" "{\"int\": 38}" 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
-        poetry run coverage run -a --source=opshin -m opshin compile spending examples/smart_contracts/assert_sum.py > assert_sum.uplc
-        poetry run coverage run -a --source=opshin -m opshin eval_uplc spending examples/smart_contracts/assert_sum.py "{\"int\": 4}" "{\"int\": 38}" 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
-        poetry run coverage run -a --source=opshin -m opshin compile_pluto spending examples/smart_contracts/assert_sum.py
-        poetry run coverage run -a --source=opshin -m opshin build spending examples/smart_contracts/assert_sum.py
+        poetry run coverage run -m pytest opshin/tests
+        poetry run coverage run -a -m opshin eval spending examples/smart_contracts/assert_sum.py "{\"int\": 4}" "{\"int\": 38}" 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
+        poetry run coverage run -a -m opshin compile spending examples/smart_contracts/assert_sum.py > assert_sum.uplc
+        poetry run coverage run -a -m opshin eval_uplc spending examples/smart_contracts/assert_sum.py "{\"int\": 4}" "{\"int\": 38}" 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
+        poetry run coverage run -a -m opshin compile_pluto spending examples/smart_contracts/assert_sum.py
+        poetry run coverage run -a -m opshin build spending examples/smart_contracts/assert_sum.py
         for i in $(find examples -type f -name "*.py" -not \( -name "broken*" -o -name "extract*" \)); do
           echo "$i"
-          poetry run coverage run -a --source=opshin -m opshin compile any "$i" > /dev/null || exit
+          poetry run coverage run -a -m opshin compile any "$i" > /dev/null || exit
         done
-        poetry run coverage run -a --source=opshin -m opshin build spending examples/smart_contracts/parameterized.py '{"int": 42}'
-        poetry run coverage run -a --source=opshin -m opshin build spending examples/smart_contracts/dual_use.py -fforce-three-params
-        poetry run coverage run -a --source=opshin -m opshin build spending examples/smart_contracts/dual_use.py -fforce-three-params -O0
-        poetry run coverage run -a --source=opshin -m opshin build spending examples/smart_contracts/dual_use.py -fforce-three-params -O1
-        poetry run coverage run -a --source=opshin -m opshin build spending examples/smart_contracts/dual_use.py -fforce-three-params -O2
-        poetry run coverage run -a --source=opshin -m opshin build spending examples/smart_contracts/dual_use.py -fforce-three-params -O3
-        poetry run coverage run -a --source=opshin -m opshin build spending examples/smart_contracts/wrapped_token.py '{"bytes": "ae810731b5d21c0d182d89c60a1eff7095dffd1c0dce8707a8611099"}' '{"bytes": "4d494c4b"}' '{"int": 1000000}' -fforce-three-params
-        test ! -n "$(poetry run coverage run -a --source=opshin -m opshin lint any examples/smart_contracts/always_true.py)"
-        test -n "$(poetry run coverage run -a --source=opshin -m opshin lint any examples/smart_contracts/wrapped_token.py)"
-        test -n "$(poetry run coverage run -a --source=opshin -m opshin lint any examples/broken.py)"
-        test -n "$(poetry run coverage run -a --source=opshin -m opshin lint any examples/broken.py --output-format-json)"
-        poetry run coverage run -a --source=opshin -m opshin compile lib opshin/prelude.py -fno-remove-dead-code
+        poetry run coverage run -a -m opshin build spending examples/smart_contracts/parameterized.py '{"int": 42}'
+        poetry run coverage run -a -m opshin build spending examples/smart_contracts/dual_use.py -fforce-three-params
+        poetry run coverage run -a -m opshin build spending examples/smart_contracts/dual_use.py -fforce-three-params -O0
+        poetry run coverage run -a -m opshin build spending examples/smart_contracts/dual_use.py -fforce-three-params -O1
+        poetry run coverage run -a -m opshin build spending examples/smart_contracts/dual_use.py -fforce-three-params -O2
+        poetry run coverage run -a -m opshin build spending examples/smart_contracts/dual_use.py -fforce-three-params -O3
+        poetry run coverage run -a -m opshin build spending examples/smart_contracts/wrapped_token.py '{"bytes": "ae810731b5d21c0d182d89c60a1eff7095dffd1c0dce8707a8611099"}' '{"bytes": "4d494c4b"}' '{"int": 1000000}' -fforce-three-params
+        test ! -n "$(poetry run coverage run -a -m opshin lint any examples/smart_contracts/always_true.py)"
+        test -n "$(poetry run coverage run -a -m opshin lint any examples/smart_contracts/wrapped_token.py)"
+        test -n "$(poetry run coverage run -a -m opshin lint any examples/broken.py)"
+        test -n "$(poetry run coverage run -a -m opshin lint any examples/broken.py --output-format-json)"
+        poetry run coverage run -a -m opshin compile lib opshin/prelude.py -fno-remove-dead-code
         for i in $(find opshin/std opshin/ledger -type f -name "*.py" ! -name "*integrity.py"); do
           echo "$i"
-          poetry run coverage run -a --source=opshin -m opshin compile lib "$i" -fno-remove-dead-code > /dev/null || exit
+          poetry run coverage run -a -m opshin compile lib "$i" -fno-remove-dead-code > /dev/null || exit
         done
 
     - name: Upload coverage data to coveralls.io
diff --git a/pyproject.toml b/pyproject.toml
index 38b1b2f5..fcfb6ad5 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -48,3 +48,33 @@ opshin = "opshin.__main__:main"
 [build-system]
 requires = ["setuptools", "poetry-core"]
 build-backend = "poetry.core.masonry.api"
+
+[tool.coverage.run]
+branch = true
+source = ["opshin"]
+
+[tool.coverage.report]
+# We dont care whether test cases got executed
+omit = [
+ "*opshin/tests/*",
+]
+# Regexes for lines to exclude from consideration
+exclude_also = [
+    # Don't complain if tests don't hit defensive assertion code:
+    "raise NotImplementedError",
+
+    # Don't complain if non-runnable code isn't run:
+    "if __name__ == .__main__.:",
+
+    # Don't complain about abstract methods, they aren't run:
+    "@(abc\\.)?abstractmethod",
+
+    # Don't complain about missing debug-only code:
+    "def __repr__",
+    ]
+
+ignore_errors = true
+
+[tool.coverage.html]
+directory = "coverage_html_report"
+