diff --git a/gtsam.h b/gtsam.h
index 0c393a433..dbd3d9fad 100644
--- a/gtsam.h
+++ b/gtsam.h
@@ -1450,11 +1450,6 @@ size_t symbol(char chr, size_t index);
 char symbolChr(size_t key);
 size_t symbolIndex(size_t key);
 
-// Key utilities
-gtsam::KeySet keyIntersection(const gtsam::KeySet& keysA, const gtsam::KeySet& keysB);
-gtsam::KeySet keyDifference(const gtsam::KeySet& keysA, const gtsam::KeySet& keysB);
-bool hasKeyIntersection(const gtsam::KeySet& keysA, const gtsam::KeySet& keysB);
-
 // Default keyformatter
 void printKeySet(const gtsam::KeySet& keys);
 void printKeySet(const gtsam::KeySet& keys, string s);
diff --git a/gtsam/nonlinear/Key.cpp b/gtsam/nonlinear/Key.cpp
index fe9f8c480..c4b21e681 100644
--- a/gtsam/nonlinear/Key.cpp
+++ b/gtsam/nonlinear/Key.cpp
@@ -60,39 +60,6 @@ void printKeySet(const gtsam::KeySet& keys, const std::string& s, const KeyForma
     std::cout << std::endl;
   }
 }
-
-/* ************************************************************************* */
-gtsam::KeySet keyIntersection(const gtsam::KeySet& keysA, const gtsam::KeySet& keysB) {
-  gtsam::KeySet intersection;
-  if (keysA.empty() || keysB.empty())
-    return intersection;
-  BOOST_FOREACH(const gtsam::Key& key, keysA)
-    if (keysB.count(key))
-      intersection.insert(key);
-  return intersection;
-}
-
-/* ************************************************************************* */
-bool hasKeyIntersection(const gtsam::KeySet& keysA, const gtsam::KeySet& keysB) {
-  if (keysA.empty() || keysB.empty())
-    return false;
-  BOOST_FOREACH(const gtsam::Key& key, keysA)
-    if (keysB.count(key))
-      return true;
-  return false;
-}
-
-/* ************************************************************************* */
-gtsam::KeySet keyDifference(const gtsam::KeySet& keysA, const gtsam::KeySet& keysB) {
-  if (keysA.empty() || keysB.empty())
-    return keysA;
-
-  gtsam::KeySet difference;
-  BOOST_FOREACH(const gtsam::Key& key, keysA)
-    if (!keysB.count(key))
-      difference.insert(key);
-  return difference;
-}
 /* ************************************************************************* */
 
 } // \namespace gtsam
diff --git a/gtsam/nonlinear/Key.h b/gtsam/nonlinear/Key.h
index bcc08d9cd..edeea396f 100644
--- a/gtsam/nonlinear/Key.h
+++ b/gtsam/nonlinear/Key.h
@@ -60,14 +60,5 @@ namespace gtsam {
   /// 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);
-
-  /// Computes the intersection between two sets
-  GTSAM_EXPORT gtsam::KeySet keyIntersection(const gtsam::KeySet& keysA, const gtsam::KeySet& keysB);
-
-  /// Checks if an intersection exists - faster checking size of above
-  GTSAM_EXPORT bool hasKeyIntersection(const gtsam::KeySet& keysA, const gtsam::KeySet& keysB);
-
-  /// Computes a difference between sets, so result is those that are in A, but not B
-  GTSAM_EXPORT gtsam::KeySet keyDifference(const gtsam::KeySet& keysA, const gtsam::KeySet& keysB);
 }