diff --git a/gtsam/inference/graph-inl.h b/gtsam/inference/graph-inl.h
index a23eda60c5..3ea66405b7 100644
--- a/gtsam/inference/graph-inl.h
+++ b/gtsam/inference/graph-inl.h
@@ -200,8 +200,8 @@ boost::shared_ptr<Values> composePoses(const G& graph, const PredecessorMap<KEY>
     boost::shared_ptr<Factor> factor = boost::dynamic_pointer_cast<Factor>(nl_factor);
     if (!factor) continue;
 
-    KEY key1 = factor->template key<1>();
-    KEY key2 = factor->template key<2>();
+    KEY key1 = factor->key1();
+    KEY key2 = factor->key2();
 
     PoseVertex v1 = key2vertex.find(key1)->second;
     PoseVertex v2 = key2vertex.find(key2)->second;
@@ -270,8 +270,8 @@ void split(const G& g, const PredecessorMap<KEY>& tree, G& Ab1, G& Ab2) {
         FACTOR2>(factor);
     if (!factor2) continue;
 
-    KEY key1 = factor2->template key<1>();
-    KEY key2 = factor2->template key<2>();
+    KEY key1 = factor2->key1();
+    KEY key2 = factor2->key2();
     // if the tree contains the key
     if ((tree.find(key1) != tree.end() &&
        tree.find(key1)->second.compare(key2) == 0) ||
diff --git a/gtsam/nonlinear/FunctorizedFactor.h b/gtsam/nonlinear/FunctorizedFactor.h
index 1fb44ebf77..1dc397c686 100644
--- a/gtsam/nonlinear/FunctorizedFactor.h
+++ b/gtsam/nonlinear/FunctorizedFactor.h
@@ -101,7 +101,7 @@ class FunctorizedFactor : public NoiseModelFactorN<T> {
       const KeyFormatter &keyFormatter = DefaultKeyFormatter) const override {
     Base::print(s, keyFormatter);
     std::cout << s << (s != "" ? " " : "") << "FunctorizedFactor("
-              << keyFormatter(this->template key<1>()) << ")" << std::endl;
+              << keyFormatter(this->key1()) << ")" << std::endl;
     traits<R>::Print(measured_, "  measurement: ");
     std::cout << "  noise model sigmas: " << noiseModel_->sigmas().transpose()
               << std::endl;
@@ -208,8 +208,8 @@ class FunctorizedFactor2 : public NoiseModelFactorN<T1, T2> {
       const KeyFormatter &keyFormatter = DefaultKeyFormatter) const override {
     Base::print(s, keyFormatter);
     std::cout << s << (s != "" ? " " : "") << "FunctorizedFactor2("
-              << keyFormatter(this->template key<1>()) << ", "
-              << keyFormatter(this->template key<2>()) << ")" << std::endl;
+              << keyFormatter(this->key1()) << ", "
+              << keyFormatter(this->key2()) << ")" << std::endl;
     traits<R>::Print(measured_, "  measurement: ");
     std::cout << "  noise model sigmas: " << noiseModel_->sigmas().transpose()
               << std::endl;
diff --git a/gtsam/nonlinear/NonlinearFactor.h b/gtsam/nonlinear/NonlinearFactor.h
index c58179db35..f6517d2810 100644
--- a/gtsam/nonlinear/NonlinearFactor.h
+++ b/gtsam/nonlinear/NonlinearFactor.h
@@ -272,6 +272,64 @@ class GTSAM_EXPORT NoiseModelFactor: public NonlinearFactor {
 
 }; // \class NoiseModelFactor
 
+/* ************************************************************************* */
+namespace detail {
+/** Convenience base class to add aliases `X1`, `X2`, ..., `X6` -> ValueType<N>.
+ * Usage example:
+ * ```
+ * class MyFactor : public NoiseModelFactorN<Pose3, Point3>,
+ *                  public NoiseModelFactorAliases<Pose3, Point3> {
+ *  // class implementation ...
+ * };
+ *
+ * // MyFactor::X1 == Pose3
+ * // MyFactor::X2 == Point3
+ * ```
+ */
+template <typename, typename...>
+struct NoiseModelFactorAliases {};
+template <typename T1>
+struct NoiseModelFactorAliases<T1> {
+  using X = T1;
+  using X1 = T1;
+};
+template <typename T1, typename T2>
+struct NoiseModelFactorAliases<T1, T2> {
+  using X1 = T1;
+  using X2 = T2;
+};
+template <typename T1, typename T2, typename T3>
+struct NoiseModelFactorAliases<T1, T2, T3> {
+  using X1 = T1;
+  using X2 = T2;
+  using X3 = T3;
+};
+template <typename T1, typename T2, typename T3, typename T4>
+struct NoiseModelFactorAliases<T1, T2, T3, T4> {
+  using X1 = T1;
+  using X2 = T2;
+  using X3 = T3;
+  using X4 = T4;
+};
+template <typename T1, typename T2, typename T3, typename T4, typename T5>
+struct NoiseModelFactorAliases<T1, T2, T3, T4, T5> {
+  using X1 = T1;
+  using X2 = T2;
+  using X3 = T3;
+  using X4 = T4;
+  using X5 = T5;
+};
+template <typename T1, typename T2, typename T3, typename T4, typename T5,
+          typename T6, typename... TExtra>
+struct NoiseModelFactorAliases<T1, T2, T3, T4, T5, T6, TExtra...> {
+  using X1 = T1;
+  using X2 = T2;
+  using X3 = T3;
+  using X4 = T4;
+  using X5 = T5;
+  using X6 = T6;
+};
+}  // namespace detail
 
 /* ************************************************************************* */
 /**
@@ -327,7 +385,9 @@ class GTSAM_EXPORT NoiseModelFactor: public NonlinearFactor {
  * objects in non-linear manifolds (Lie groups).
  */
 template <class... ValueTypes>
-class NoiseModelFactorN : public NoiseModelFactor {
+class NoiseModelFactorN
+    : public NoiseModelFactor,
+      public detail::NoiseModelFactorAliases<ValueTypes...> {
  public:
   /// N is the number of variables (N-way factor)
   enum { N = sizeof...(ValueTypes) };
@@ -377,6 +437,14 @@ class NoiseModelFactorN : public NoiseModelFactor {
    * // Factor::ValueType<0> // ERROR!  Will not compile.
    * // Factor::ValueType<3> // ERROR!  Will not compile.
    * ```
+   *
+   * You can also use the shortcuts `X1`, ..., `X6` which are the same as
+   * `ValueType<1>`, ..., `ValueType<6>` respectively (see
+   * detail::NoiseModelFactorAliases).
+   *
+   * Note that, if your class is templated AND you want to use `ValueType<1>`
+   * inside your class, due to dependent types you need the `template` keyword:
+   * `typename MyFactor<T>::template ValueType<1>`.
    */
   template <int I, typename = IndexIsValid<I>>
   using ValueType =
@@ -431,6 +499,10 @@ class NoiseModelFactorN : public NoiseModelFactor {
    * // key<0>()  // ERROR!  Will not compile
    * // key<3>()  // ERROR!  Will not compile
    * ```
+   * 
+   * Note that, if your class is templated AND you are trying to call `key<1>`
+   * inside your class, due to dependent types you need the `template` keyword:
+   * `this->key1()`.
    */
   template <int I = 1>
   inline Key key() const {
@@ -555,37 +627,34 @@ class NoiseModelFactorN : public NoiseModelFactor {
   }
 
  public:
-  /// @name Deprecated methods.  Use `key<1>()`, `key<2>()`, ... instead of old
-  /// `key1()`, `key2()`, ...
-  /// If your class is templated AND you are trying to call `key<1>` inside your
-  /// class, due to dependent types you need to do `this->template key<1>()`.
+  /// @name Shortcut functions `key1()` -> `key<1>()`
   /// @{
 
-  inline Key GTSAM_DEPRECATED key1() const {
+  inline Key key1() const {
     return key<1>();
   }
   template <int I = 2>
-  inline Key GTSAM_DEPRECATED key2() const {
+  inline Key key2() const {
     static_assert(I <= N, "Index out of bounds");
     return key<2>();
   }
   template <int I = 3>
-  inline Key GTSAM_DEPRECATED key3() const {
+  inline Key key3() const {
     static_assert(I <= N, "Index out of bounds");
     return key<3>();
   }
   template <int I = 4>
-  inline Key GTSAM_DEPRECATED key4() const {
+  inline Key key4() const {
     static_assert(I <= N, "Index out of bounds");
     return key<4>();
   }
   template <int I = 5>
-  inline Key GTSAM_DEPRECATED key5() const {
+  inline Key key5() const {
     static_assert(I <= N, "Index out of bounds");
     return key<5>();
   }
   template <int I = 6>
-  inline Key GTSAM_DEPRECATED key6() const {
+  inline Key key6() const {
     static_assert(I <= N, "Index out of bounds");
     return key<6>();
   }
@@ -594,268 +663,11 @@ class NoiseModelFactorN : public NoiseModelFactor {
 
 };  // \class NoiseModelFactorN
 
-/* ************************************************************************* */
-/** @deprecated: use NoiseModelFactorN, replacing .key() with .key<1>() and X1
- * with ValueType<1>.
- * If your class is templated AND you are trying to call `.key<1>()` or
- * `ValueType<1>` inside your class, due to dependent types you need to do
- * `this->template key<1>()` or `This::template ValueType<1>`.
- * ~~~
- * A convenient base class for creating your own NoiseModelFactor
- * with 1 variable.  To derive from this class, implement evaluateError().
- */
-template <class VALUE>
-class GTSAM_DEPRECATED NoiseModelFactor1 : public NoiseModelFactorN<VALUE> {
- public:
-  /** Aliases for value types pulled from keys, for backwards compatibility.
-   * Note: in your code you can probably just do:
-   *  `using X = ValueType<1>;`
-   * but this class is uglier due to dependent types.
-   * See e.g. testNonlinearFactor.cpp:TestFactorN.
-   */
-  using X = typename NoiseModelFactor1::template ValueType<1>;
-
- protected:
-  using Base = NoiseModelFactor;  // grandparent, for backwards compatibility
-  using This = NoiseModelFactor1<VALUE>;
-
- public:
-  // inherit NoiseModelFactorN's constructors
-  using NoiseModelFactorN<VALUE>::NoiseModelFactorN;
-  ~NoiseModelFactor1() override {}
-
- private:
-  /** Serialization function */
-  friend class boost::serialization::access;
-  template <class ARCHIVE>
-  void serialize(ARCHIVE& ar, const unsigned int /*version*/) {
-    ar& boost::serialization::make_nvp(
-        "NoiseModelFactor", boost::serialization::base_object<Base>(*this));
-  }
-};  // \class NoiseModelFactor1
-
-/* ************************************************************************* */
-/** @deprecated: use NoiseModelFactorN, replacing .key1() with .key<1>() and X1
- * with ValueType<1>.
- * If your class is templated AND you are trying to call `.key<1>()` or
- * `ValueType<1>` inside your class, due to dependent types you need to do
- * `this->template key<1>()` or `This::template ValueType<1>`.
- * ~~~
- * A convenient base class for creating your own NoiseModelFactor
- * with 2 variables.  To derive from this class, implement evaluateError().
- */
-template <class VALUE1, class VALUE2>
-class GTSAM_DEPRECATED NoiseModelFactor2
-    : public NoiseModelFactorN<VALUE1, VALUE2> {
- public:
-  /** Aliases for value types pulled from keys.
-   * Note: in your code you can probably just do: 
-   *  `using X1 = ValueType<1>;`
-   * but this class is uglier due to dependent types.
-   * See e.g. testNonlinearFactor.cpp:TestFactorN.
-   */
-  using X1 = typename NoiseModelFactor2::template ValueType<1>;
-  using X2 = typename NoiseModelFactor2::template ValueType<2>;
-
- protected:
-  using Base = NoiseModelFactor;
-  using This = NoiseModelFactor2<VALUE1, VALUE2>;
-
- public:
-  // inherit NoiseModelFactorN's constructors
-  using NoiseModelFactorN<VALUE1, VALUE2>::NoiseModelFactorN;
-  ~NoiseModelFactor2() override {}
-
- private:
-  /** Serialization function */
-  friend class boost::serialization::access;
-  template <class ARCHIVE>
-  void serialize(ARCHIVE& ar, const unsigned int /*version*/) {
-    ar& boost::serialization::make_nvp(
-        "NoiseModelFactor", boost::serialization::base_object<Base>(*this));
-  }
-};  // \class NoiseModelFactor2
-
-/* ************************************************************************* */
-/** @deprecated: use NoiseModelFactorN, replacing .key1() with .key<1>() and X1
- * with ValueType<1>.
- * If your class is templated AND you are trying to call `.key<1>()` or
- * `ValueType<1>` inside your class, due to dependent types you need to do
- * `this->template key<1>()` or `This::template ValueType<1>`.
- * ~~~
- * A convenient base class for creating your own NoiseModelFactor
- * with 3 variables.  To derive from this class, implement evaluateError().
- */
-template <class VALUE1, class VALUE2, class VALUE3>
-class GTSAM_DEPRECATED NoiseModelFactor3
-    : public NoiseModelFactorN<VALUE1, VALUE2, VALUE3> {
- public:
-  /** Aliases for value types pulled from keys.
-   * Note: in your code you can probably just do: 
-   *  `using X1 = ValueType<1>;`
-   * but this class is uglier due to dependent types.
-   * See e.g. testNonlinearFactor.cpp:TestFactorN.
-   */
-  using X1 = typename NoiseModelFactor3::template ValueType<1>;
-  using X2 = typename NoiseModelFactor3::template ValueType<2>;
-  using X3 = typename NoiseModelFactor3::template ValueType<3>;
-
- protected:
-  using Base = NoiseModelFactor;
-  using This = NoiseModelFactor3<VALUE1, VALUE2, VALUE3>;
-
- public:
-  // inherit NoiseModelFactorN's constructors
-  using NoiseModelFactorN<VALUE1, VALUE2, VALUE3>::NoiseModelFactorN;
-  ~NoiseModelFactor3() override {}
-
- private:
-  /** Serialization function */
-  friend class boost::serialization::access;
-  template <class ARCHIVE>
-  void serialize(ARCHIVE& ar, const unsigned int /*version*/) {
-    ar& boost::serialization::make_nvp(
-        "NoiseModelFactor", boost::serialization::base_object<Base>(*this));
-  }
-};  // \class NoiseModelFactor3
-
-/* ************************************************************************* */
-/** @deprecated: use NoiseModelFactorN, replacing .key1() with .key<1>() and X1
- * with ValueType<1>.
- * If your class is templated AND you are trying to call `.key<1>()` or
- * `ValueType<1>` inside your class, due to dependent types you need to do
- * `this->template key<1>()` or `This::template ValueType<1>`.
- * ~~~
- * A convenient base class for creating your own NoiseModelFactor
- * with 4 variables.  To derive from this class, implement evaluateError().
- */
-template <class VALUE1, class VALUE2, class VALUE3, class VALUE4>
-class GTSAM_DEPRECATED NoiseModelFactor4
-    : public NoiseModelFactorN<VALUE1, VALUE2, VALUE3, VALUE4> {
- public:
-  /** Aliases for value types pulled from keys.
-   * Note: in your code you can probably just do: 
-   *  `using X1 = ValueType<1>;`
-   * but this class is uglier due to dependent types.
-   * See e.g. testNonlinearFactor.cpp:TestFactorN.
-   */
-  using X1 = typename NoiseModelFactor4::template ValueType<1>;
-  using X2 = typename NoiseModelFactor4::template ValueType<2>;
-  using X3 = typename NoiseModelFactor4::template ValueType<3>;
-  using X4 = typename NoiseModelFactor4::template ValueType<4>;
-
- protected:
-  using Base = NoiseModelFactor;
-  using This = NoiseModelFactor4<VALUE1, VALUE2, VALUE3, VALUE4>;
-
- public:
-  // inherit NoiseModelFactorN's constructors
-  using NoiseModelFactorN<VALUE1, VALUE2, VALUE3, VALUE4>::NoiseModelFactorN;
-  ~NoiseModelFactor4() override {}
-
- private:
-  /** Serialization function */
-  friend class boost::serialization::access;
-  template <class ARCHIVE>
-  void serialize(ARCHIVE& ar, const unsigned int /*version*/) {
-    ar& boost::serialization::make_nvp(
-        "NoiseModelFactor", boost::serialization::base_object<Base>(*this));
-  }
-};  // \class NoiseModelFactor4
-
-/* ************************************************************************* */
-/** @deprecated: use NoiseModelFactorN, replacing .key1() with .key<1>() and X1
- * with ValueType<1>.
- * If your class is templated AND you are trying to call `.key<1>()` or
- * `ValueType<1>` inside your class, due to dependent types you need to do
- * `this->template key<1>()` or `This::template ValueType<1>`.
- * ~~~
- * A convenient base class for creating your own NoiseModelFactor
- * with 5 variables.  To derive from this class, implement evaluateError().
- */
-template <class VALUE1, class VALUE2, class VALUE3, class VALUE4, class VALUE5>
-class GTSAM_DEPRECATED NoiseModelFactor5
-    : public NoiseModelFactorN<VALUE1, VALUE2, VALUE3, VALUE4, VALUE5> {
- public:
-  /** Aliases for value types pulled from keys.
-   * Note: in your code you can probably just do: 
-   *  `using X1 = ValueType<1>;`
-   * but this class is uglier due to dependent types.
-   * See e.g. testNonlinearFactor.cpp:TestFactorN.
-   */
-  using X1 = typename NoiseModelFactor5::template ValueType<1>;
-  using X2 = typename NoiseModelFactor5::template ValueType<2>;
-  using X3 = typename NoiseModelFactor5::template ValueType<3>;
-  using X4 = typename NoiseModelFactor5::template ValueType<4>;
-  using X5 = typename NoiseModelFactor5::template ValueType<5>;
-
- protected:
-  using Base = NoiseModelFactor;
-  using This = NoiseModelFactor5<VALUE1, VALUE2, VALUE3, VALUE4, VALUE5>;
-
- public:
-  // inherit NoiseModelFactorN's constructors
-  using NoiseModelFactorN<VALUE1, VALUE2, VALUE3, VALUE4,
-                          VALUE5>::NoiseModelFactorN;
-  ~NoiseModelFactor5() override {}
-
- private:
-  /** Serialization function */
-  friend class boost::serialization::access;
-  template <class ARCHIVE>
-  void serialize(ARCHIVE& ar, const unsigned int /*version*/) {
-    ar& boost::serialization::make_nvp(
-        "NoiseModelFactor", boost::serialization::base_object<Base>(*this));
-  }
-};  // \class NoiseModelFactor5
-
-/* ************************************************************************* */
-/** @deprecated: use NoiseModelFactorN, replacing .key1() with .key<1>() and X1
- * with ValueType<1>.
- * If your class is templated AND you are trying to call `.key<1>()` or
- * `ValueType<1>` inside your class, due to dependent types you need to do
- * `this->template key<1>()` or `This::template ValueType<1>`.
- * ~~~
- * A convenient base class for creating your own NoiseModelFactor
- * with 6 variables.  To derive from this class, implement evaluateError().
- */
-template <class VALUE1, class VALUE2, class VALUE3, class VALUE4, class VALUE5,
-          class VALUE6>
-class GTSAM_DEPRECATED NoiseModelFactor6
-    : public NoiseModelFactorN<VALUE1, VALUE2, VALUE3, VALUE4, VALUE5, VALUE6> {
- public:
-  /** Aliases for value types pulled from keys.
-   * Note: in your code you can probably just do: 
-   *  `using X1 = ValueType<1>;`
-   * but this class is uglier due to dependent types.
-   * See e.g. testNonlinearFactor.cpp:TestFactorN.
-   */
-  using X1 = typename NoiseModelFactor6::template ValueType<1>;
-  using X2 = typename NoiseModelFactor6::template ValueType<2>;
-  using X3 = typename NoiseModelFactor6::template ValueType<3>;
-  using X4 = typename NoiseModelFactor6::template ValueType<4>;
-  using X5 = typename NoiseModelFactor6::template ValueType<5>;
-  using X6 = typename NoiseModelFactor6::template ValueType<6>;
-
- protected:
-  using Base = NoiseModelFactor;
-  using This =
-      NoiseModelFactor6<VALUE1, VALUE2, VALUE3, VALUE4, VALUE5, VALUE6>;
-
- public:
-  // inherit NoiseModelFactorN's constructors
-  using NoiseModelFactorN<VALUE1, VALUE2, VALUE3, VALUE4, VALUE5,
-                          VALUE6>::NoiseModelFactorN;
-  ~NoiseModelFactor6() override {}
-
- private:
-  /** Serialization function */
-  friend class boost::serialization::access;
-  template <class ARCHIVE>
-  void serialize(ARCHIVE& ar, const unsigned int /*version*/) {
-    ar& boost::serialization::make_nvp(
-        "NoiseModelFactor", boost::serialization::base_object<Base>(*this));
-  }
-};  // \class NoiseModelFactor6
+#define NoiseModelFactor1 NoiseModelFactorN
+#define NoiseModelFactor2 NoiseModelFactorN
+#define NoiseModelFactor3 NoiseModelFactorN
+#define NoiseModelFactor4 NoiseModelFactorN
+#define NoiseModelFactor5 NoiseModelFactorN
+#define NoiseModelFactor6 NoiseModelFactorN
 
-} // \namespace gtsam
+}  // namespace gtsam
diff --git a/gtsam/slam/BetweenFactor.h b/gtsam/slam/BetweenFactor.h
index f2b41e0a1c..d420e2b54d 100644
--- a/gtsam/slam/BetweenFactor.h
+++ b/gtsam/slam/BetweenFactor.h
@@ -88,8 +88,8 @@ namespace gtsam {
         const std::string& s = "",
         const KeyFormatter& keyFormatter = DefaultKeyFormatter) const override {
       std::cout << s << "BetweenFactor("
-          << keyFormatter(this->template key<1>()) << ","
-          << keyFormatter(this->template key<2>()) << ")\n";
+          << keyFormatter(this->key1()) << ","
+          << keyFormatter(this->key2()) << ")\n";
       traits<T>::Print(measured_, "  measured: ");
       this->noiseModel_->print("  noise model: ");
     }
diff --git a/gtsam/slam/BoundingConstraint.h b/gtsam/slam/BoundingConstraint.h
index 79890ec944..bd20668d84 100644
--- a/gtsam/slam/BoundingConstraint.h
+++ b/gtsam/slam/BoundingConstraint.h
@@ -129,7 +129,7 @@ struct BoundingConstraint2: public NoiseModelFactorN<VALUE1, VALUE2> {
   /** active when constraint *NOT* met */
   bool active(const Values& c) const override {
     // note: still active at equality to avoid zigzagging
-    double x = value(c.at<X1>(this->template key<1>()), c.at<X2>(this->template key<2>()));
+    double x = value(c.at<X1>(this->key1()), c.at<X2>(this->key2()));
     return (isGreaterThan_) ? x <= threshold_ : x >= threshold_;
   }
 
diff --git a/gtsam/slam/FrobeniusFactor.h b/gtsam/slam/FrobeniusFactor.h
index 60f880a7a9..2e7e28d033 100644
--- a/gtsam/slam/FrobeniusFactor.h
+++ b/gtsam/slam/FrobeniusFactor.h
@@ -130,8 +130,8 @@ class FrobeniusBetweenFactor : public NoiseModelFactorN<Rot, Rot> {
   print(const std::string &s,
         const KeyFormatter &keyFormatter = DefaultKeyFormatter) const override {
     std::cout << s << "FrobeniusBetweenFactor<" << demangle(typeid(Rot).name())
-              << ">(" << keyFormatter(this->template key<1>()) << ","
-              << keyFormatter(this->template key<2>()) << ")\n";
+              << ">(" << keyFormatter(this->key1()) << ","
+              << keyFormatter(this->key2()) << ")\n";
     traits<Rot>::Print(R12_, "  R12: ");
     this->noiseModel_->print("  noise model: ");
   }
diff --git a/gtsam/slam/GeneralSFMFactor.h b/gtsam/slam/GeneralSFMFactor.h
index f3089bd71f..37296c0d88 100644
--- a/gtsam/slam/GeneralSFMFactor.h
+++ b/gtsam/slam/GeneralSFMFactor.h
@@ -140,7 +140,7 @@ class GeneralSFMFactor: public NoiseModelFactorN<CAMERA, LANDMARK> {
     // Only linearize if the factor is active
     if (!this->active(values)) return boost::shared_ptr<JacobianFactor>();
 
-    const Key key1 = this->template key<1>(), key2 = this->template key<2>();
+    const Key key1 = this->key1(), key2 = this->key2();
     JacobianC H1;
     JacobianL H2;
     Vector2 b;
@@ -270,8 +270,8 @@ class GeneralSFMFactor2: public NoiseModelFactorN<Pose3, Point3, CALIBRATION> {
       if (H1) *H1 = Matrix::Zero(2, 6);
       if (H2) *H2 = Matrix::Zero(2, 3);
       if (H3) *H3 = Matrix::Zero(2, DimK);
-      std::cout << e.what() << ": Landmark "<< DefaultKeyFormatter(this->template key<2>())
-      << " behind Camera " << DefaultKeyFormatter(this->template key<1>()) << std::endl;
+      std::cout << e.what() << ": Landmark "<< DefaultKeyFormatter(this->key2())
+      << " behind Camera " << DefaultKeyFormatter(this->key1()) << std::endl;
     }
     return Z_2x1;
   }
diff --git a/gtsam/slam/ProjectionFactor.h b/gtsam/slam/ProjectionFactor.h
index add6c86c4c..c90fc80d58 100644
--- a/gtsam/slam/ProjectionFactor.h
+++ b/gtsam/slam/ProjectionFactor.h
@@ -154,10 +154,10 @@ namespace gtsam {
         if (H1) *H1 = Matrix::Zero(2,6);
         if (H2) *H2 = Matrix::Zero(2,3);
         if (verboseCheirality_)
-          std::cout << e.what() << ": Landmark "<< DefaultKeyFormatter(this->template key<2>()) <<
-              " moved behind camera " << DefaultKeyFormatter(this->template key<1>()) << std::endl;
+          std::cout << e.what() << ": Landmark "<< DefaultKeyFormatter(this->key2()) <<
+              " moved behind camera " << DefaultKeyFormatter(this->key1()) << std::endl;
         if (throwCheirality_)
-          throw CheiralityException(this->template key<2>());
+          throw CheiralityException(this->key2());
       }
       return Vector2::Constant(2.0 * K_->fx());
     }
diff --git a/gtsam/slam/ReferenceFrameFactor.h b/gtsam/slam/ReferenceFrameFactor.h
index 74e8444046..383c81cc47 100644
--- a/gtsam/slam/ReferenceFrameFactor.h
+++ b/gtsam/slam/ReferenceFrameFactor.h
@@ -107,16 +107,16 @@ class ReferenceFrameFactor : public NoiseModelFactorN<POINT, TRANSFORM, POINT> {
   void print(const std::string& s="",
       const gtsam::KeyFormatter& keyFormatter = DefaultKeyFormatter) const override {
     std::cout << s << ": ReferenceFrameFactor("
-        << "Global: " << keyFormatter(this->template key<1>()) << ","
-        << " Transform: " << keyFormatter(this->template key<2>()) << ","
-        << " Local: " << keyFormatter(this->template key<3>()) << ")\n";
+        << "Global: " << keyFormatter(this->key1()) << ","
+        << " Transform: " << keyFormatter(this->key2()) << ","
+        << " Local: " << keyFormatter(this->key3()) << ")\n";
     this->noiseModel_->print("  noise model");
   }
 
   // access - convenience functions
-  Key global_key() const { return this->template key<1>(); }
-  Key transform_key() const { return this->template key<2>(); }
-  Key local_key() const { return this->template key<3>(); }
+  Key global_key() const { return this->key1(); }
+  Key transform_key() const { return this->key2(); }
+  Key local_key() const { return this->key3(); }
 
 private:
   /** Serialization function */
diff --git a/gtsam/slam/StereoFactor.h b/gtsam/slam/StereoFactor.h
index 1d2ef501d6..1013b22b1d 100644
--- a/gtsam/slam/StereoFactor.h
+++ b/gtsam/slam/StereoFactor.h
@@ -141,10 +141,10 @@ class GenericStereoFactor: public NoiseModelFactorN<POSE, LANDMARK> {
       if (H1) *H1 = Matrix::Zero(3,6);
       if (H2) *H2 = Z_3x3;
       if (verboseCheirality_)
-      std::cout << e.what() << ": Landmark "<< DefaultKeyFormatter(this->template key<2>()) <<
-          " moved behind camera " << DefaultKeyFormatter(this->template key<1>()) << std::endl;
+      std::cout << e.what() << ": Landmark "<< DefaultKeyFormatter(this->key2()) <<
+          " moved behind camera " << DefaultKeyFormatter(this->key1()) << std::endl;
       if (throwCheirality_)
-        throw StereoCheiralityException(this->template key<2>());
+        throw StereoCheiralityException(this->key2());
     }
     return Vector3::Constant(2.0 * K_->fx());
   }
diff --git a/gtsam_unstable/slam/EquivInertialNavFactor_GlobalVel.h b/gtsam_unstable/slam/EquivInertialNavFactor_GlobalVel.h
index 43001fbc2a..e52837fb4e 100644
--- a/gtsam_unstable/slam/EquivInertialNavFactor_GlobalVel.h
+++ b/gtsam_unstable/slam/EquivInertialNavFactor_GlobalVel.h
@@ -136,11 +136,11 @@ class EquivInertialNavFactor_GlobalVel : public NoiseModelFactorN<POSE, VELOCITY
   /** print */
   void print(const std::string& s = "EquivInertialNavFactor_GlobalVel", const KeyFormatter& keyFormatter = DefaultKeyFormatter) const override {
     std::cout << s << "("
-        << keyFormatter(this->template key<1>()) << ","
-        << keyFormatter(this->template key<2>()) << ","
-        << keyFormatter(this->template key<3>()) << ","
-        << keyFormatter(this->template key<4>()) << ","
-        << keyFormatter(this->template key<5>()) << "\n";
+        << keyFormatter(this->key1()) << ","
+        << keyFormatter(this->key2()) << ","
+        << keyFormatter(this->key3()) << ","
+        << keyFormatter(this->key4()) << ","
+        << keyFormatter(this->key5()) << "\n";
     std::cout << "delta_pos_in_t0: " << this->delta_pos_in_t0_.transpose() << std::endl;
     std::cout << "delta_vel_in_t0: " << this->delta_vel_in_t0_.transpose() << std::endl;
     std::cout << "delta_angles: " << this->delta_angles_ << std::endl;
diff --git a/gtsam_unstable/slam/GaussMarkov1stOrderFactor.h b/gtsam_unstable/slam/GaussMarkov1stOrderFactor.h
index c3682e536d..5d677b82e6 100644
--- a/gtsam_unstable/slam/GaussMarkov1stOrderFactor.h
+++ b/gtsam_unstable/slam/GaussMarkov1stOrderFactor.h
@@ -73,8 +73,8 @@ class GaussMarkov1stOrderFactor: public NoiseModelFactorN<VALUE, VALUE> {
   /** print */
   void print(const std::string& s, const KeyFormatter& keyFormatter = DefaultKeyFormatter) const override {
     std::cout << s << "GaussMarkov1stOrderFactor("
-        << keyFormatter(this->template key<1>()) << ","
-        << keyFormatter(this->template key<2>()) << ")\n";
+        << keyFormatter(this->key1()) << ","
+        << keyFormatter(this->key2()) << ")\n";
     this->noiseModel_->print("  noise model");
   }
 
diff --git a/gtsam_unstable/slam/InertialNavFactor_GlobalVelocity.h b/gtsam_unstable/slam/InertialNavFactor_GlobalVelocity.h
index efaf71d229..fd3ab729d1 100644
--- a/gtsam_unstable/slam/InertialNavFactor_GlobalVelocity.h
+++ b/gtsam_unstable/slam/InertialNavFactor_GlobalVelocity.h
@@ -117,11 +117,11 @@ class InertialNavFactor_GlobalVelocity : public NoiseModelFactorN<POSE, VELOCITY
   /** print */
   void print(const std::string& s = "InertialNavFactor_GlobalVelocity", const KeyFormatter& keyFormatter = DefaultKeyFormatter) const override {
     std::cout << s << "("
-        << keyFormatter(this->template key<1>()) << ","
-        << keyFormatter(this->template key<2>()) << ","
-        << keyFormatter(this->template key<3>()) << ","
-        << keyFormatter(this->template key<4>()) << ","
-        << keyFormatter(this->template key<5>()) << "\n";
+        << keyFormatter(this->key1()) << ","
+        << keyFormatter(this->key2()) << ","
+        << keyFormatter(this->key3()) << ","
+        << keyFormatter(this->key4()) << ","
+        << keyFormatter(this->key5()) << "\n";
     std::cout << "acc measurement: " << this->measurement_acc_.transpose() << std::endl;
     std::cout << "gyro measurement: " << this->measurement_gyro_.transpose() << std::endl;
     std::cout << "dt: " << this->dt_ << std::endl;
diff --git a/gtsam_unstable/slam/InvDepthFactor3.h b/gtsam_unstable/slam/InvDepthFactor3.h
index 59a834f0b7..2d0d57437f 100644
--- a/gtsam_unstable/slam/InvDepthFactor3.h
+++ b/gtsam_unstable/slam/InvDepthFactor3.h
@@ -93,8 +93,8 @@ class InvDepthFactor3: public NoiseModelFactorN<POSE, LANDMARK, INVDEPTH> {
       if (H1) *H1 = Matrix::Zero(2,6);
       if (H2) *H2 = Matrix::Zero(2,5);
       if (H3) *H3 = Matrix::Zero(2,1);
-      std::cout << e.what() << ": Landmark "<< DefaultKeyFormatter(this->template key<2>()) <<
-          " moved behind camera " << DefaultKeyFormatter(this->template key<1>()) << std::endl;
+      std::cout << e.what() << ": Landmark "<< DefaultKeyFormatter(this->key2()) <<
+          " moved behind camera " << DefaultKeyFormatter(this->key1()) << std::endl;
       return Vector::Ones(2) * 2.0 * K_->fx();
     }
     return (Vector(1) << 0.0).finished();
diff --git a/gtsam_unstable/slam/PoseBetweenFactor.h b/gtsam_unstable/slam/PoseBetweenFactor.h
index 676e011de2..aaf00b45d1 100644
--- a/gtsam_unstable/slam/PoseBetweenFactor.h
+++ b/gtsam_unstable/slam/PoseBetweenFactor.h
@@ -68,8 +68,8 @@ namespace gtsam {
     /** print */
     void print(const std::string& s, const KeyFormatter& keyFormatter = DefaultKeyFormatter) const override {
       std::cout << s << "BetweenFactor("
-          << keyFormatter(this->template key<1>()) << ","
-          << keyFormatter(this->template key<2>()) << ")\n";
+          << keyFormatter(this->key1()) << ","
+          << keyFormatter(this->key2()) << ")\n";
       measured_.print("  measured: ");
       if(this->body_P_sensor_)
         this->body_P_sensor_->print("  sensor pose in body frame: ");
diff --git a/gtsam_unstable/slam/PoseToPointFactor.h b/gtsam_unstable/slam/PoseToPointFactor.h
index ad1ba5fbe6..0d295113d6 100644
--- a/gtsam_unstable/slam/PoseToPointFactor.h
+++ b/gtsam_unstable/slam/PoseToPointFactor.h
@@ -48,8 +48,8 @@ class PoseToPointFactor : public NoiseModelFactorN<POSE, POINT> {
   void print(const std::string& s, const KeyFormatter& keyFormatter =
                                        DefaultKeyFormatter) const override {
     std::cout << s << "PoseToPointFactor("
-              << keyFormatter(this->template key<1>()) << ","
-              << keyFormatter(this->template key<2>()) << ")\n"
+              << keyFormatter(this->key1()) << ","
+              << keyFormatter(this->key2()) << ")\n"
               << "  measured: " << measured_.transpose() << std::endl;
     this->noiseModel_->print("  noise model: ");
   }
diff --git a/gtsam_unstable/slam/ProjectionFactorPPP.h b/gtsam_unstable/slam/ProjectionFactorPPP.h
index 8962b31b2d..ab8cba4816 100644
--- a/gtsam_unstable/slam/ProjectionFactorPPP.h
+++ b/gtsam_unstable/slam/ProjectionFactorPPP.h
@@ -143,9 +143,9 @@ namespace gtsam {
         if (H3) *H3 = Matrix::Zero(2,3);
         if (verboseCheirality_)
             std::cout << e.what() << ": Landmark "
-                      << DefaultKeyFormatter(this->template key<2>())
+                      << DefaultKeyFormatter(this->key2())
                       << " moved behind camera "
-                      << DefaultKeyFormatter(this->template key<1>())
+                      << DefaultKeyFormatter(this->key1())
                       << std::endl;
         if (throwCheirality_)
           throw e;
diff --git a/gtsam_unstable/slam/ProjectionFactorPPPC.h b/gtsam_unstable/slam/ProjectionFactorPPPC.h
index afbf858382..dec893af48 100644
--- a/gtsam_unstable/slam/ProjectionFactorPPPC.h
+++ b/gtsam_unstable/slam/ProjectionFactorPPPC.h
@@ -130,8 +130,8 @@ class GTSAM_UNSTABLE_EXPORT ProjectionFactorPPPC
         if (H3) *H3 = Matrix::Zero(2,3);
         if (H4) *H4 = Matrix::Zero(2,CALIBRATION::Dim());
         if (verboseCheirality_)
-          std::cout << e.what() << ": Landmark "<< DefaultKeyFormatter(this->template key<2>()) <<
-              " moved behind camera " << DefaultKeyFormatter(this->template key<1>()) << std::endl;
+          std::cout << e.what() << ": Landmark "<< DefaultKeyFormatter(this->key2()) <<
+              " moved behind camera " << DefaultKeyFormatter(this->key1()) << std::endl;
         if (throwCheirality_)
           throw e;
       }
diff --git a/tests/testNonlinearFactor.cpp b/tests/testNonlinearFactor.cpp
index c536a48c3f..c823614502 100644
--- a/tests/testNonlinearFactor.cpp
+++ b/tests/testNonlinearFactor.cpp
@@ -330,13 +330,6 @@ TEST( NonlinearFactor, cloneWithNewNoiseModel )
 }
 
 /* ************************************************************************* */
-// Suppress deprecation warnings while we are testing backwards compatibility
-#define IGNORE_DEPRECATED_PUSH                              \
-  CLANG_DIAGNOSTIC_PUSH_IGNORE("-Wdeprecated-declarations") \
-  GCC_DIAGNOSTIC_PUSH_IGNORE("-Wdeprecated-declarations")   \
-  MSVC_DIAGNOSTIC_PUSH_IGNORE(4996)
-/* ************************************************************************* */
-IGNORE_DEPRECATED_PUSH
 class TestFactor1 : public NoiseModelFactor1<double> {
   static_assert(std::is_same<Base, NoiseModelFactor>::value, "Base type wrong");
   static_assert(std::is_same<This, NoiseModelFactor1<double>>::value,
@@ -358,7 +351,6 @@ class TestFactor1 : public NoiseModelFactor1<double> {
         gtsam::NonlinearFactor::shared_ptr(new TestFactor1(*this)));
   }
 };
-DIAGNOSTIC_POP()
 
 /* ************************************ */
 TEST(NonlinearFactor, NoiseModelFactor1) {
@@ -388,7 +380,6 @@ TEST(NonlinearFactor, NoiseModelFactor1) {
 }
 
 /* ************************************************************************* */
-IGNORE_DEPRECATED_PUSH
 class TestFactor4 : public NoiseModelFactor4<double, double, double, double> {
   static_assert(std::is_same<Base, NoiseModelFactor>::value, "Base type wrong");
   static_assert(
@@ -420,7 +411,6 @@ class TestFactor4 : public NoiseModelFactor4<double, double, double, double> {
     return boost::static_pointer_cast<gtsam::NonlinearFactor>(
         gtsam::NonlinearFactor::shared_ptr(new TestFactor4(*this))); }
 };
-DIAGNOSTIC_POP()
 
 /* ************************************ */
 TEST(NonlinearFactor, NoiseModelFactor4) {
@@ -444,7 +434,6 @@ TEST(NonlinearFactor, NoiseModelFactor4) {
   EXPECT(assert_equal((Vector)(Vector(1) << 0.5 * -30.).finished(), jf.getb()));
 
   // Test all functions/types for backwards compatibility
-  IGNORE_DEPRECATED_PUSH
   static_assert(std::is_same<TestFactor4::X1, double>::value,
                 "X1 type incorrect");
   static_assert(std::is_same<TestFactor4::X2, double>::value,
@@ -463,7 +452,6 @@ TEST(NonlinearFactor, NoiseModelFactor4) {
   EXPECT(assert_equal((Matrix)(Matrix(1, 1) << 2.).finished(), H.at(1)));
   EXPECT(assert_equal((Matrix)(Matrix(1, 1) << 3.).finished(), H.at(2)));
   EXPECT(assert_equal((Matrix)(Matrix(1, 1) << 4.).finished(), H.at(3)));
-  DIAGNOSTIC_POP()
 
   // And test "forward compatibility" using `key<N>` and `ValueType<N>` too
   static_assert(std::is_same<TestFactor4::ValueType<1>, double>::value,
@@ -489,7 +477,6 @@ TEST(NonlinearFactor, NoiseModelFactor4) {
 }
 
 /* ************************************************************************* */
-IGNORE_DEPRECATED_PUSH
 class TestFactor5 : public NoiseModelFactor5<double, double, double, double, double> {
 public:
   typedef NoiseModelFactor5<double, double, double, double, double> Base;
@@ -513,7 +500,6 @@ class TestFactor5 : public NoiseModelFactor5<double, double, double, double, dou
         .finished();
   }
 };
-DIAGNOSTIC_POP()
 
 /* ************************************ */
 TEST(NonlinearFactor, NoiseModelFactor5) {
@@ -541,7 +527,6 @@ TEST(NonlinearFactor, NoiseModelFactor5) {
 }
 
 /* ************************************************************************* */
-IGNORE_DEPRECATED_PUSH
 class TestFactor6 : public NoiseModelFactor6<double, double, double, double, double, double> {
 public:
   typedef NoiseModelFactor6<double, double, double, double, double, double> Base;
@@ -569,7 +554,6 @@ class TestFactor6 : public NoiseModelFactor6<double, double, double, double, dou
   }
 
 };
-DIAGNOSTIC_POP()
 
 /* ************************************ */
 TEST(NonlinearFactor, NoiseModelFactor6) {
@@ -673,11 +657,11 @@ TEST(NonlinearFactor, NoiseModelFactorN) {
   EXPECT(assert_equal(H4_expected, H4));
 
   // Test all functions/types for backwards compatibility
-  IGNORE_DEPRECATED_PUSH
+
   static_assert(std::is_same<TestFactor4::X1, double>::value,
                 "X1 type incorrect");
   EXPECT(assert_equal(tf.key3(), X(3)));
-  DIAGNOSTIC_POP()
+
 
   // Test using `key<N>` and `ValueType<N>`
   static_assert(std::is_same<TestFactorN::ValueType<1>, double>::value,