diff --git a/.github/workflows/main.yaml b/.github/workflows/main.yaml
index a59b6a3..ef1d0f6 100644
--- a/.github/workflows/main.yaml
+++ b/.github/workflows/main.yaml
@@ -28,10 +28,7 @@ jobs:
         python -m pip install --upgrade pip
         pip install -r requirements-test.txt
     - name: Lint
-      # FIXME
-      continue-on-error: true
-      run: |
-        flake8 lib/pyld tests --count --show-source --statistics
+      run: make lint
   test:
     runs-on: ubuntu-latest
     timeout-minutes: 10
diff --git a/Makefile b/Makefile
index 838f84b..594d886 100644
--- a/Makefile
+++ b/Makefile
@@ -7,4 +7,17 @@ test:
 	pytest
 
 upgrade-submodules:
-	git submodule update --remote --init --recursive
\ No newline at end of file
+	git submodule update --remote --init --recursive
+
+# At this stage, we are limiting our formatting efforts to one file. We need to ensure that:
+# * our formatting rules are sane,
+# * we are not introducing conflicts with currently open PRs,
+# * and the PR introducing `ruff` is not too large.
+RUFF_TARGET = lib/pyld/context_resolver.py
+
+lint:
+	ruff check $(RUFF_TARGET)
+
+fmt:
+	ruff check --fix $(RUFF_TARGET)
+	ruff format $(RUFF_TARGET)
diff --git a/lib/pyld/context_resolver.py b/lib/pyld/context_resolver.py
index 784821a..7cee671 100644
--- a/lib/pyld/context_resolver.py
+++ b/lib/pyld/context_resolver.py
@@ -9,8 +9,10 @@
 """
 
 from frozendict import frozendict
+
 from c14n.Canonicalize import canonicalize
-from pyld import jsonld, iri_resolver
+from pyld import iri_resolver, jsonld
+
 from .resolved_context import ResolvedContext
 
 MAX_CONTEXT_URLS = 10
@@ -42,7 +44,7 @@ def resolve(self, active_ctx, context, base, cycles=None):
             cycles = set()
 
         # process `@context`
-        if (isinstance(context, dict) or isinstance(context, frozendict)) and '@context' in context:
+        if isinstance(context, (dict, frozendict)) and '@context' in context:
             context = context['@context']
 
         # context is one or more contexts
@@ -154,7 +156,7 @@ def _fetch_context(self, active_ctx, url, cycles):
                 'provided for a remote context.',
                 'jsonld.InvalidUrl',
                 {'url': url, 'cause': cause},
-                code='loading remote context failed')
+                code='loading remote context failed') from cause
 
         # ensure ctx is an object
         if not isinstance(context, dict) and not isinstance(context, frozendict):
@@ -201,7 +203,7 @@ def _resolve_context_urls(self, context, base):
             for num, element in enumerate(ctx):
                 if isinstance(element, str):
                     ctx[num] = iri_resolver.resolve(element, base)
-                elif isinstance(element, dict) or isinstance(element, frozendict):
+                elif isinstance(element, (dict, frozendict)):
                     self. _resolve_context_urls({'@context': element}, base)
             return
 
diff --git a/pyproject.toml b/pyproject.toml
new file mode 100644
index 0000000..b596e81
--- /dev/null
+++ b/pyproject.toml
@@ -0,0 +1,57 @@
+[tool.ruff]
+# Target Python version
+target-version = "py310"
+
+# Line length (matching rdflib's flake8 config)
+line-length = 88
+
+# Include and exclude patterns
+include = ["*.py"]
+exclude = [
+    ".git",
+    "__pycache__",
+    ".venv",
+    "venv",
+    "build",
+    "dist",
+    "*.egg-info",
+]
+
+[tool.ruff.lint]
+# Enable common rule sets
+select = [
+    "E",   # pycodestyle errors
+    "W",   # pycodestyle warnings
+    "F",   # pyflakes
+    "I",   # isort (import sorting)
+    "N",   # pep8-naming
+    "UP",  # pyupgrade
+    "B",   # flake8-bugbear
+    "C4",  # flake8-comprehensions
+    "SIM", # flake8-simplify
+]
+
+# Ignore specific rules if needed
+ignore = [
+    "E501",  # line too long (handled by formatter, matches rdflib's flake8)
+    "F821",  # undefined name (matches rdflib's flake8 W806 ignore)
+    "Q000",  # quote style (preserved by formatter)
+    "Q001",  # quote style (preserved by formatter)
+    "Q002",  # quote style (preserved by formatter)
+    "Q003",  # quote style (preserved by formatter)
+]
+
+[tool.ruff.format]
+# Preserve existing quote styles (don't enforce single or double quotes)
+quote-style = "preserve"
+# Indent with spaces
+indent-style = "space"
+# Use 4 spaces for indentation
+skip-magic-trailing-comma = false
+# Line ending style
+line-ending = "auto"
+
+[tool.ruff.lint.isort]
+# Import sorting configuration
+known-first-party = ["pyld", "c14n"]
+
diff --git a/requirements-test.txt b/requirements-test.txt
index aad120b..68fc11a 100644
--- a/requirements-test.txt
+++ b/requirements-test.txt
@@ -1,2 +1,2 @@
-flake8
-pytest
\ No newline at end of file
+ruff
+pytest