diff --git a/gtsam/inference/Key.h b/gtsam/inference/Key.h
index 2cc19d07a..31428a50e 100644
--- a/gtsam/inference/Key.h
+++ b/gtsam/inference/Key.h
@@ -32,7 +32,7 @@
 namespace gtsam {
 
 /// Typedef for a function to format a key, i.e. to convert it to a string
-typedef std::function<std::string(Key)> KeyFormatter;
+using KeyFormatter = std::function<std::string(Key)>;
 
 // Helper function for DefaultKeyFormatter
 GTSAM_EXPORT std::string _defaultKeyFormatter(Key key);
@@ -83,28 +83,32 @@ class key_formatter {
 };
 
 /// Define collection type once and for all - also used in wrappers
-typedef FastVector<Key> KeyVector;
+using KeyVector = FastVector<Key>;
 
 // TODO(frank): Nothing fast about these :-(
-typedef FastList<Key> KeyList;
-typedef FastSet<Key> KeySet;
-typedef FastMap<Key, int> KeyGroupMap;
+using KeyList = FastList<Key>;
+using KeySet = FastSet<Key>;
+using KeyGroupMap = FastMap<Key, int>;
 
 /// Utility function to print one key with optional prefix
-GTSAM_EXPORT void PrintKey(Key key, const std::string& s = "",
-    const KeyFormatter& keyFormatter = DefaultKeyFormatter);
+GTSAM_EXPORT void PrintKey(
+    Key key, const std::string &s = "",
+    const KeyFormatter &keyFormatter = DefaultKeyFormatter);
 
 /// Utility function to print sets of keys with optional prefix
-GTSAM_EXPORT void PrintKeyList(const KeyList& keys, const std::string& s = "",
-    const KeyFormatter& keyFormatter = DefaultKeyFormatter);
+GTSAM_EXPORT void PrintKeyList(
+    const KeyList &keys, const std::string &s = "",
+    const KeyFormatter &keyFormatter = DefaultKeyFormatter);
 
 /// Utility function to print sets of keys with optional prefix
-GTSAM_EXPORT void PrintKeyVector(const KeyVector& keys, const std::string& s =
-    "", const KeyFormatter& keyFormatter = DefaultKeyFormatter);
+GTSAM_EXPORT void PrintKeyVector(
+    const KeyVector &keys, const std::string &s = "",
+    const KeyFormatter &keyFormatter = DefaultKeyFormatter);
 
 /// Utility function to print sets of keys with optional prefix
-GTSAM_EXPORT void PrintKeySet(const KeySet& keys, const std::string& s = "",
-    const KeyFormatter& keyFormatter = DefaultKeyFormatter);
+GTSAM_EXPORT void PrintKeySet(
+    const KeySet &keys, const std::string &s = "",
+    const KeyFormatter &keyFormatter = DefaultKeyFormatter);
 
 // Define Key to be Testable by specializing gtsam::traits
 template<typename T> struct traits;