diff --git a/.pre-commit-config.yaml b/.pre-commit-config.yaml
index ba6a2c5..c3a170c 100644
--- a/.pre-commit-config.yaml
+++ b/.pre-commit-config.yaml
@@ -94,6 +94,18 @@ repos:
         language: unsupported
         pass_filenames: false
         always_run: true
+        # https://youtu.be/70T6OxKwxm0
+      - id: test-coverage
+        name: Tests have 100% run coverage
+        entry: >
+          coverage report
+          --no-skip-covered
+          --include 'tests/*'
+          --fail-under 100
+        stages: ["pre-push"]
+        language: unsupported
+        pass_filenames: false
+        always_run: true
       - id: coverage-badge
         name: Generate coverage badge
         entry: >
diff --git a/coverage.svg b/coverage.svg
index ef52bd2..7175bd1 100644
--- a/coverage.svg
+++ b/coverage.svg
@@ -1 +1 @@
-<svg xmlns="http://www.w3.org/2000/svg" width="122" height="20" role="img" aria-label="coverage: 100.00%"><title>coverage: 100.00%</title><linearGradient id="s" x2="0" y2="100%"><stop offset="0" stop-color="#bbb" stop-opacity=".1"/><stop offset="1" stop-opacity=".1"/></linearGradient><clipPath id="r"><rect width="122" height="20" rx="3" fill="#fff"/></clipPath><g clip-path="url(#r)"><rect width="61" height="20" fill="#555"/><rect x="61" width="61" height="20" fill="#4c1"/><rect width="122" height="20" fill="url(#s)"/></g><g fill="#fff" text-anchor="middle" font-family="Verdana,Geneva,DejaVu Sans,sans-serif" text-rendering="geometricPrecision" font-size="110"><text aria-hidden="true" x="315" y="150" fill="#010101" fill-opacity=".3" transform="scale(.1)" textLength="510">coverage</text><text x="315" y="140" transform="scale(.1)" fill="#fff" textLength="510">coverage</text><text aria-hidden="true" x="905" y="150" fill="#010101" fill-opacity=".3" transform="scale(.1)" textLength="510">100.00%</text><text x="905" y="140" transform="scale(.1)" fill="#fff" textLength="510">100.00%</text></g></svg>
\ No newline at end of file
+<svg xmlns="http://www.w3.org/2000/svg" width="122" height="20" role="img" aria-label="coverage: 100.00%"><title>coverage: 100.00%</title><filter id="blur"><feGaussianBlur in="SourceGraphic" stdDeviation="16"/></filter><linearGradient id="s" x2="0" y2="100%"><stop offset="0" stop-color="#bbb" stop-opacity=".1"/><stop offset="1" stop-opacity=".1"/></linearGradient><clipPath id="r"><rect width="122" height="20" rx="3" fill="#fff"/></clipPath><g clip-path="url(#r)"><rect width="61" height="20" fill="#555"/><rect x="61" width="61" height="20" fill="#4b0"/><rect width="122" height="20" fill="url(#s)"/></g><g fill="#fff" text-anchor="middle" font-family="Verdana,Geneva,DejaVu Sans,sans-serif" text-rendering="geometricPrecision" font-size="110"><text aria-hidden="true" x="315" y="150" fill="#010101" fill-opacity=".80" filter="url(#blur)" transform="scale(.1)" textLength="510">coverage</text><text aria-hidden="true" x="315" y="150" fill="#010101" fill-opacity=".3" transform="scale(.1)" textLength="510">coverage</text><text x="315" y="140" transform="scale(.1)" fill="#fff" textLength="510">coverage</text><text aria-hidden="true" x="905" y="150" fill="#010101" fill-opacity=".80" filter="url(#blur)" transform="scale(.1)" textLength="510">100.00%</text><text aria-hidden="true" x="905" y="150" fill="#010101" fill-opacity=".3" transform="scale(.1)" textLength="510">100.00%</text><text x="905" y="140" transform="scale(.1)" fill="#fff" textLength="510">100.00%</text></g></svg>
\ No newline at end of file
diff --git a/pyproject.toml b/pyproject.toml
index 6905e33..2bc2520 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -20,6 +20,7 @@ dev = [
     "pre-commit>=4.5.1",
 ]
 test = [
+    "covdefaults>=2.3.0",
     "pytest>=9.0.3",
     "pytest-cov>=7.0.0",
 ]
@@ -73,11 +74,12 @@ shell = """
 
 
 [tool.pytest.ini_options]
-addopts = "--cov=src"
+addopts = "--cov"
 testpaths = ["tests"]
 
 [tool.coverage]
 run.branch = true
+run.plugins = ["covdefaults"]  # https://youtu.be/70T6OxKwxm0
 report.fail_under = 80
 report.show_missing = true