diff --git a/capa/features/extractors/base_extractor.py b/capa/features/extractors/base_extractor.py
index 4b6be1ee..c287e75b 100644
--- a/capa/features/extractors/base_extractor.py
+++ b/capa/features/extractors/base_extractor.py
@@ -58,7 +58,7 @@ class FeatureExtractor:
         fetch the preferred load address at which the sample was analyzed.
         """
         raise NotImplemented
- 
+
     @abc.abstractmethod
     def extract_global_features(self) -> Iterator[Tuple[Feature, int]]:
         """
@@ -74,7 +74,7 @@ class FeatureExtractor:
           Tuple[Feature, int]: feature and its location
         """
         raise NotImplemented
- 
+
     @abc.abstractmethod
     def extract_file_features(self) -> Iterator[Tuple[Feature, int]]:
         """
@@ -272,12 +272,12 @@ class NullFeatureExtractor(FeatureExtractor):
 
     def get_base_address(self):
         return self.features["base address"]
-                                             
+
     def extract_global_features(self):
         for p in self.features.get("global features", []):
             va, feature = p
             yield feature, va
-                                             
+
     def extract_file_features(self):
         for p in self.features.get("file features", []):
             va, feature = p
diff --git a/capa/features/extractors/pefile.py b/capa/features/extractors/pefile.py
index a204107c..8f6a3ed1 100644
--- a/capa/features/extractors/pefile.py
+++ b/capa/features/extractors/pefile.py
@@ -150,7 +150,7 @@ FILE_HANDLERS = (
     extract_file_function_names,
     extract_file_format,
 )
- 
+
 
 def extract_global_features(pe, buf):
     """
diff --git a/capa/features/freeze.py b/capa/features/freeze.py
index 42e3d8c9..9c0d0c98 100644
--- a/capa/features/freeze.py
+++ b/capa/features/freeze.py
@@ -192,7 +192,7 @@ def loads(s):
         va = int(va, 0x10)
         feature = deserialize_feature(feature[:2])
         features["global features"].append((va, feature))
- 
+
     for feature in doc.get("scopes", {}).get("file", []):
         va, loc = feature[2:]
         va = int(va, 0x10)
diff --git a/capa/main.py b/capa/main.py
index ef380581..a7e1fb8a 100644
--- a/capa/main.py
+++ b/capa/main.py
@@ -88,12 +88,16 @@ def find_function_capabilities(ruleset: RuleSet, extractor: FeatureExtractor, f:
         #  - basic blocks
         bb_features = collections.defaultdict(set)
 
-        for feature, va in itertools.chain(extractor.extract_basic_block_features(f, bb), extractor.extract_global_features()):
+        for feature, va in itertools.chain(
+            extractor.extract_basic_block_features(f, bb), extractor.extract_global_features()
+        ):
             bb_features[feature].add(va)
             function_features[feature].add(va)
 
         for insn in extractor.get_instructions(f, bb):
-            for feature, va in itertools.chain(extractor.extract_insn_features(f, bb, insn), extractor.extract_global_features()):
+            for feature, va in itertools.chain(
+                extractor.extract_insn_features(f, bb, insn), extractor.extract_global_features()
+            ):
                 bb_features[feature].add(va)
                 function_features[feature].add(va)
 
diff --git a/tests/fixtures.py b/tests/fixtures.py
index 8283502d..1b404bb2 100644
--- a/tests/fixtures.py
+++ b/tests/fixtures.py
@@ -139,7 +139,7 @@ def extract_global_features(extractor):
     for feature, va in extractor.extract_global_features():
         features[feature].add(va)
     return features
- 
+
 
 @lru_cache()
 def extract_file_features(extractor):