diff --git a/Makefile b/Makefile
index fe5d9a595b9..f9463804401 100644
--- a/Makefile
+++ b/Makefile
@@ -6,7 +6,6 @@ PYTEST_COV_ARGS=--cov=$(PROJECT) --cov-config=../pyproject.toml \
 			--pyargs ${PYTEST_EXTRA}
 FORMAT_FILES=$(PROJECT) doc/conf.py examples
 LINT_FILES=$(PROJECT) doc/conf.py
-BLACKDOC_OPTIONS=--line-length 79
 
 help:
 	@echo "Commands:"
@@ -54,13 +53,13 @@ format:
 	isort .
 	docformatter --in-place $(FORMAT_FILES)
 	black $(FORMAT_FILES)
-	blackdoc $(BLACKDOC_OPTIONS) $(FORMAT_FILES)
+	blackdoc $(FORMAT_FILES)
 
 check:
 	isort . --check
 	docformatter --check $(FORMAT_FILES)
 	black --check $(FORMAT_FILES)
-	blackdoc --check $(BLACKDOC_OPTIONS) $(FORMAT_FILES)
+	blackdoc --check $(FORMAT_FILES)
 	FLAKEHEAVEN_CACHE_TIMEOUT=0 flakeheaven lint $(FORMAT_FILES)
 
 lint:
diff --git a/pyproject.toml b/pyproject.toml
index 4783f3def84..69e727f0d8c 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -59,6 +59,9 @@ tests = ["data/*", "baseline/*"]
 local_scheme = "node-and-date"
 fallback_version = "999.999.999+unknown"
 
+[tool.blackdoc]
+line-length = 79
+
 [tool.coverage.run]
 omit = ["*/tests/*", "*pygmt/__init__.py"]