diff --git a/cmake/GtsamCythonWrap.cmake b/cmake/GtsamCythonWrap.cmake
index ec297955b..2c6d4808a 100644
--- a/cmake/GtsamCythonWrap.cmake
+++ b/cmake/GtsamCythonWrap.cmake
@@ -52,7 +52,7 @@ function(pyx_to_cpp target pyx_file generated_cpp include_dirs)
   add_custom_command(
     OUTPUT ${generated_cpp}
     COMMAND
-      ${CYTHON_EXECUTABLE} -a -v --cplus ${includes_for_cython} ${pyx_file} -o ${generated_cpp}
+      ${CYTHON_EXECUTABLE} -X boundscheck=False -a -v --cplus ${includes_for_cython} ${pyx_file} -o ${generated_cpp}
     VERBATIM)
   add_custom_target(${target} ALL DEPENDS ${generated_cpp})
 endfunction()
diff --git a/wrap/Argument.cpp b/wrap/Argument.cpp
index 6455297c4..913c11284 100644
--- a/wrap/Argument.cpp
+++ b/wrap/Argument.cpp
@@ -281,15 +281,16 @@ std::string ArgumentList::pyx_paramsList() const {
 }
 
 /* ************************************************************************* */
-std::string ArgumentList::pyx_castParamsToPythonType() const {
-  if (size() == 0) 
-    return "            pass\n";
+std::string ArgumentList::pyx_castParamsToPythonType(
+    const std::string& indent) const {
+  if (size() == 0)
+    return "";
 
   // cast params to their correct python argument type to pass in the function call later
   string s;
   for (size_t j = 0; j < size(); ++j)
-    s += "            " + at(j).name + " = <" + at(j).type.pyxArgumentType()
-             + ">(__params['" + at(j).name + "'])\n";
+    s += indent + at(j).name + " = <" + at(j).type.pyxArgumentType()
+        + ">(__params[" + std::to_string(j) + "])\n";
   return s;
 }
 
diff --git a/wrap/Argument.h b/wrap/Argument.h
index c06e4f797..0a4ebba9d 100644
--- a/wrap/Argument.h
+++ b/wrap/Argument.h
@@ -131,7 +131,7 @@ struct ArgumentList: public std::vector<Argument> {
   void emit_cython_pyx(FileWriter& file) const;
   std::string pyx_asParams() const;
   std::string pyx_paramsList() const;
-  std::string pyx_castParamsToPythonType() const;
+  std::string pyx_castParamsToPythonType(const std::string& indent) const;
   std::string pyx_convertEigenTypeAndStorageOrder(const std::string& indent) const;
 
   /**
diff --git a/wrap/Class.cpp b/wrap/Class.cpp
index a2e42cb1c..5192ee4d3 100644
--- a/wrap/Class.cpp
+++ b/wrap/Class.cpp
@@ -837,7 +837,7 @@ void Class::emit_cython_pyx(FileWriter& pyxFile, const std::vector<Class>& allCl
   for (size_t i = 0; i<constructor.nrOverloads(); ++i) {
     pyxFile.oss << "        " << "elif" << " self."
                 << pyxClassName() << "_" << i
-                << "(*args, **kwargs):\n            pass\n";
+                << "(args, kwargs):\n            pass\n";
   }
   pyxFile.oss << "        else:\n            raise TypeError('" << pyxClassName()
               << " construction failed!')\n";
@@ -855,10 +855,10 @@ void Class::emit_cython_pyx(FileWriter& pyxFile, const std::vector<Class>& allCl
               << shared_pxd_class_in_pyx() << "& other):\n"
               << "        if other.get() == NULL:\n"
               << "            raise RuntimeError('Cannot create object from a nullptr!')\n"
-              << "        cdef " << pyxClassName() << " ret = " << pyxClassName() << "(cyCreateFromShared=True)\n"
-              << "        ret." << shared_pxd_obj_in_pyx() << " = other\n";
-  pyxInitParentObj(pyxFile, "        ret", "other", allClasses);
-  pyxFile.oss << "        return ret" << "\n";
+              << "        cdef " << pyxClassName() << " return_value = " << pyxClassName() << "(cyCreateFromShared=True)\n"
+              << "        return_value." << shared_pxd_obj_in_pyx() << " = other\n";
+  pyxInitParentObj(pyxFile, "        return_value", "other", allClasses);
+  pyxFile.oss << "        return return_value" << "\n\n";
 
   for(const StaticMethod& m: static_methods | boost::adaptors::map_values)
     m.emit_cython_pyx(pyxFile, *this);
diff --git a/wrap/Constructor.cpp b/wrap/Constructor.cpp
index b2ebbce4c..09746bfdb 100644
--- a/wrap/Constructor.cpp
+++ b/wrap/Constructor.cpp
@@ -145,15 +145,21 @@ void Constructor::emit_cython_pxd(FileWriter& pxdFile, const Class& cls) const {
 void Constructor::emit_cython_pyx(FileWriter& pyxFile, const Class& cls) const {
   for (size_t i = 0; i < nrOverloads(); i++) {
     ArgumentList args = argumentList(i);
-    pyxFile.oss << "    def " + cls.pyxClassName() + "_" + to_string(i) +
-                    "(self, *args, **kwargs):\n";
-    pyxFile.oss << pyx_resolveOverloadParams(args, true);
-    pyxFile.oss << argumentList(i).pyx_convertEigenTypeAndStorageOrder("        ");
+    pyxFile.oss
+        << "    def " + cls.pyxClassName() + "_" + to_string(i)
+            + "(self, args, kwargs):\n";
+    pyxFile.oss << "        cdef list __params\n";
+    pyxFile.oss << "        try:\n";
+    pyxFile.oss << pyx_resolveOverloadParams(args, true, 3);
+    pyxFile.oss
+        << argumentList(i).pyx_convertEigenTypeAndStorageOrder("            ");
 
-    pyxFile.oss << "        self." << cls.shared_pxd_obj_in_pyx() << " = "
-                << cls.shared_pxd_class_in_pyx() << "(new " << cls.pxd_class_in_pyx()
-                << "(" << args.pyx_asParams() << "))\n";
-    pyxFile.oss << "        return True\n\n";
+    pyxFile.oss << "            self." << cls.shared_pxd_obj_in_pyx() << " = "
+        << cls.shared_pxd_class_in_pyx() << "(new " << cls.pxd_class_in_pyx()
+        << "(" << args.pyx_asParams() << "))\n";
+    pyxFile.oss << "            return True\n";
+    pyxFile.oss << "        except:\n";
+    pyxFile.oss << "            return False\n\n";
   }
 }
 
diff --git a/wrap/GlobalFunction.cpp b/wrap/GlobalFunction.cpp
index ff5c32d65..c8482f2c4 100644
--- a/wrap/GlobalFunction.cpp
+++ b/wrap/GlobalFunction.cpp
@@ -155,9 +155,11 @@ void GlobalFunction::emit_cython_pyx_no_overload(FileWriter& file) const {
 
   // Function definition
   file.oss << "def " << funcName;
+
   // modify name of function instantiation as python doesn't allow overloads
   // e.g. template<T={A,B,C}> funcName(...) --> funcNameA, funcNameB, funcNameC
   if (templateArgValue_) file.oss << templateArgValue_->pyxClassName();
+
   // funtion arguments
   file.oss << "(";
   argumentList(0).emit_cython_pyx(file);
@@ -189,28 +191,33 @@ void GlobalFunction::emit_cython_pyx(FileWriter& file) const {
   file.oss << "def " << funcName << "(*args, **kwargs):\n";
   for (size_t i = 0; i < N; ++i) {
     file.oss << "    success, results = " << funcName << "_" << i
-             << "(*args, **kwargs)\n";
+             << "(args, kwargs)\n";
     file.oss << "    if success:\n            return results\n";
   }
   file.oss << "    raise TypeError('Could not find the correct overload')\n";
 
   for (size_t i = 0; i < N; ++i) {
     ArgumentList args = argumentList(i);
-    file.oss << "def " + funcName + "_" + to_string(i) +
-                    "(*args, **kwargs):\n";
-    file.oss << pyx_resolveOverloadParams(args, false, 1); // lazy: always return None even if it's a void function
-
-    /// Call cython corresponding function
-    file.oss << argumentList(i).pyx_convertEigenTypeAndStorageOrder("    ");
-    string ret = pyx_functionCall("", pxdName(), i);
+    file.oss << "def " + funcName + "_" + to_string(i) + "(args, kwargs):\n";
+    file.oss << "    cdef list __params\n";
     if (!returnVals_[i].isVoid()) {
-      file.oss << "    cdef " << returnVals_[i].pyx_returnType()
-              << " ret = " << ret << "\n";
-      file.oss << "    return True, " << returnVals_[i].pyx_casting("ret") << "\n";
-    } else {
-      file.oss << "    " << ret << "\n";
-      file.oss << "    return True, None\n";
+      file.oss << "    cdef " << returnVals_[i].pyx_returnType() << " return_value\n";
     }
+    file.oss << "    try:\n";
+    file.oss << pyx_resolveOverloadParams(args, false, 2); // lazy: always return None even if it's a void function
+
+    /// Call corresponding cython function
+    file.oss << argumentList(i).pyx_convertEigenTypeAndStorageOrder("        ");
+    string call = pyx_functionCall("", pxdName(), i);
+    if (!returnVals_[i].isVoid()) {
+      file.oss << "        return_value = " << call << "\n";
+      file.oss << "        return True, " << returnVals_[i].pyx_casting("return_value") << "\n";
+    } else {
+      file.oss << "        " << call << "\n";
+      file.oss << "        return True, None\n";
+    }
+    file.oss << "    except:\n";
+    file.oss << "        return False, None\n\n";
   }
 }
 /* ************************************************************************* */
diff --git a/wrap/Method.cpp b/wrap/Method.cpp
index bbe341807..69bbf35ed 100644
--- a/wrap/Method.cpp
+++ b/wrap/Method.cpp
@@ -99,20 +99,23 @@ void Method::emit_cython_pxd(FileWriter& file, const Class& cls) const {
 void Method::emit_cython_pyx_no_overload(FileWriter& file,
                                          const Class& cls) const {
   string funcName = pyRename(name_);
+
   // leverage python's special treatment for print
   if (funcName == "print_") {
-    //file.oss << "    def __str__(self):\n        self.print_('')\n        return ''\n";
     file.oss << "    def __str__(self):\n";
     file.oss << "        strBuf = RedirectCout()\n";
     file.oss << "        self.print_('')\n";
     file.oss << "        return strBuf.str()\n";
   }
+
   // Function definition
   file.oss << "    def " << funcName;
+
   // modify name of function instantiation as python doesn't allow overloads
   // e.g. template<T={A,B,C}> funcName(...) --> funcNameA, funcNameB, funcNameC
   if (templateArgValue_) file.oss << templateArgValue_->pyxClassName();
-  // funtion arguments
+
+  // function arguments
   file.oss << "(self";
   if (argumentList(0).size() > 0) file.oss << ", ";
   argumentList(0).emit_cython_pyx(file);
@@ -151,7 +154,7 @@ void Method::emit_cython_pyx(FileWriter& file, const Class& cls) const {
   file.oss << "    def " << instantiatedName << "(self, *args, **kwargs):\n";
   for (size_t i = 0; i < N; ++i) {
     file.oss << "        success, results = self." << instantiatedName << "_" << i
-             << "(*args, **kwargs)\n";
+             << "(args, kwargs)\n";
     file.oss << "        if success:\n            return results\n";
   }
   file.oss << "        raise TypeError('Could not find the correct overload')\n";
@@ -159,22 +162,28 @@ void Method::emit_cython_pyx(FileWriter& file, const Class& cls) const {
   for (size_t i = 0; i < N; ++i) {
     ArgumentList args = argumentList(i);
     file.oss << "    def " + instantiatedName + "_" + to_string(i) +
-                    "(self, *args, **kwargs):\n";
-    file.oss << pyx_resolveOverloadParams(args, false); // lazy: always return None even if it's a void function
+                    "(self, args, kwargs):\n";
+    file.oss << "        cdef list __params\n";
+    if (!returnVals_[i].isVoid()) {
+      file.oss << "        cdef " << returnVals_[i].pyx_returnType() << " return_value\n";
+    }
+    file.oss << "        try:\n";
+    file.oss << pyx_resolveOverloadParams(args, false, 3); // lazy: always return None even if it's a void function
 
-    /// Call cython corresponding function
-    file.oss << argumentList(i).pyx_convertEigenTypeAndStorageOrder("        ");
+    /// Call corresponding cython function
+    file.oss << argumentList(i).pyx_convertEigenTypeAndStorageOrder("            ");
     string caller = "self." + cls.shared_pxd_obj_in_pyx() + ".get()";
 
-    string ret = pyx_functionCall(caller, funcName, i);
+    string call = pyx_functionCall(caller, funcName, i);
     if (!returnVals_[i].isVoid()) {
-      file.oss << "        cdef " << returnVals_[i].pyx_returnType()
-              << " ret = " << ret << "\n";
-      file.oss << "        return True, " << returnVals_[i].pyx_casting("ret") << "\n";
+      file.oss << "            return_value = " << call << "\n";
+      file.oss << "            return True, " << returnVals_[i].pyx_casting("return_value") << "\n";
     } else {
-      file.oss << "        " << ret << "\n";
-      file.oss << "        return True, None\n";
+      file.oss << "            " << call << "\n";
+      file.oss << "            return True, None\n";
     }
+    file.oss << "        except:\n";
+    file.oss << "            return False, None\n\n";
   }
 }
 /* ************************************************************************* */
diff --git a/wrap/Module.cpp b/wrap/Module.cpp
index 0c019303b..ac822e64b 100644
--- a/wrap/Module.cpp
+++ b/wrap/Module.cpp
@@ -412,6 +412,17 @@ void Module::emit_cython_pyx(FileWriter& pyxFile) const {
                  "from "<< pxdHeader << " cimport dynamic_pointer_cast\n"
                  "from "<< pxdHeader << " cimport make_shared\n";
 
+  pyxFile.oss << "# C helper function that copies all arguments into a positional list.\n"
+                 "cdef list process_args(list keywords, tuple args, dict kwargs):\n"
+                 "   cdef str keyword\n"
+                 "   cdef int n = len(args), m = len(keywords)\n"
+                 "   cdef list params = list(args)\n"
+                 "   assert len(args)+len(kwargs) == m, 'Expected {} arguments'.format(m)\n"
+                 "   try:\n"
+                 "       return params + [kwargs[keyword] for keyword in keywords[n:]]\n"
+                 "   except:\n"
+                 "       raise ValueError('Epected arguments ' + str(keywords))\n";
+
   // import all typedefs, e.g. from gtsam_wrapper cimport Key, so we don't need to say gtsam.Key
   for(const Qualified& q: Qualified::BasicTypedefs) {
     pyxFile.oss << "from " << pxdHeader << " cimport " << q.pxdClassName() << "\n";
diff --git a/wrap/OverloadedFunction.h b/wrap/OverloadedFunction.h
index 71acf822b..6bcb72d94 100644
--- a/wrap/OverloadedFunction.h
+++ b/wrap/OverloadedFunction.h
@@ -71,35 +71,29 @@ public:
     return os;
   }
 
-  std::string pyx_resolveOverloadParams(const ArgumentList& args, bool isVoid, size_t indentLevel = 2) const {
+  std::string pyx_resolveOverloadParams(const ArgumentList& args, bool isVoid,
+      size_t indentLevel = 2) const {
     std::string indent;
-    for (size_t i = 0; i<indentLevel; ++i) indent += "    ";
+    for (size_t i = 0; i < indentLevel; ++i)
+      indent += "    ";
     std::string s;
-    s += indent + "if len(args)+len(kwargs) !=" + std::to_string(args.size()) + ":\n";
-    s += indent + "    return False";
-    s += (!isVoid) ? ", None\n" : "\n";
+    s += indent + "__params = process_args([" + args.pyx_paramsList()
+        + "], args, kwargs)\n";
+    s += args.pyx_castParamsToPythonType(indent);
     if (args.size() > 0) {
-      s += indent + "__params = kwargs.copy()\n";
-      s += indent + "__names = [" + args.pyx_paramsList() + "]\n";
-      s += indent + "for i in range(len(args)):\n"; 
-      s += indent + "    __params[__names[i]] = args[i]\n";
-      for (size_t i = 0; i<args.size(); ++i) {
+      for (size_t i = 0; i < args.size(); ++i) {
+        // For python types we can do the assert after the assignment and save list accesses
         if (args[i].type.isNonBasicType() || args[i].type.isEigen()) {
-          std::string param = "__params[__names[" + std::to_string(i) + "]]";
-          s += indent + "if not isinstance(" + param + ", " +
-               args[i].type.pyxArgumentType() + ")";
-          if (args[i].type.isEigen())
-            s += " or not " + param + ".ndim == " +
-                 ((args[i].type.pyxClassName() == "Vector") ? "1" : "2");
-          s +=  ":\n";
-          s += indent + "    return False" + ((isVoid) ? "" : ", None") + "\n";
+          std::string param = args[i].name;
+          s += indent + "assert isinstance(" + param + ", "
+              + args[i].type.pyxArgumentType() + ")";
+          if (args[i].type.isEigen()) {
+            s += " and " + param + ".ndim == "
+                + ((args[i].type.pyxClassName() == "Vector") ? "1" : "2");
+          }
+          s += "\n";
         }
       }
-      s += indent + "try:\n";
-      s += args.pyx_castParamsToPythonType();
-      s += indent + "except:\n";
-      s += indent + "    return False";
-      s += (!isVoid) ? ", None\n" : "\n";
     }
     return s;
   }
diff --git a/wrap/StaticMethod.cpp b/wrap/StaticMethod.cpp
index e60228199..68824c157 100644
--- a/wrap/StaticMethod.cpp
+++ b/wrap/StaticMethod.cpp
@@ -80,12 +80,12 @@ void StaticMethod::emit_cython_pyx_no_overload(FileWriter& file,
 
   /// Call cython corresponding function and return
   file.oss << argumentList(0).pyx_convertEigenTypeAndStorageOrder("        ");
-  string ret = pyx_functionCall(cls.pxd_class_in_pyx(), name_, 0);
+  string call = pyx_functionCall(cls.pxd_class_in_pyx(), name_, 0);
   file.oss << "        ";
   if (!returnVals_[0].isVoid()) {
-    file.oss << "return " << returnVals_[0].pyx_casting(ret) << "\n";
+    file.oss << "return " << returnVals_[0].pyx_casting(call) << "\n";
   } else
-    file.oss << ret << "\n";
+    file.oss << call << "\n";
   file.oss << "\n";
 }
 
@@ -98,15 +98,15 @@ void StaticMethod::emit_cython_pyx(FileWriter& file, const Class& cls) const {
   }
 
   // Dealing with overloads..
-  file.oss << "    @staticmethod\n";
+  file.oss << "    @staticmethod # overloaded\n";
   file.oss << "    def " << name_ << "(*args, **kwargs):\n";
   for (size_t i = 0; i < N; ++i) {
     string funcName = name_ + "_" + to_string(i);
     file.oss << "        success, results = " << cls.pyxClassName() << "."
-             << funcName << "(*args, **kwargs)\n";
+             << funcName << "(args, kwargs)\n";
     file.oss << "        if success:\n            return results\n";
   }
-  file.oss << "        raise TypeError('Could not find the correct overload')\n";
+  file.oss << "        raise TypeError('Could not find the correct overload')\n\n";
 
   for(size_t i = 0; i < N; ++i) {
     file.oss << "    @staticmethod\n";
@@ -114,22 +114,26 @@ void StaticMethod::emit_cython_pyx(FileWriter& file, const Class& cls) const {
     string funcName = name_ + "_" + to_string(i);
     string pxdFuncName = name_ + ((i>0)?"_" + to_string(i):"");
     ArgumentList args = argumentList(i);
-    file.oss << "    def " + funcName + "(*args, **kwargs):\n";
-    file.oss << pyx_resolveOverloadParams(args, false); // lazy: always return None even if it's a void function
+    file.oss << "    def " + funcName + "(args, kwargs):\n";
+    file.oss << "        cdef list __params\n";
+    if (!returnVals_[i].isVoid()) {
+      file.oss << "        cdef " << returnVals_[i].pyx_returnType() << " return_value\n";
+    }
+    file.oss << "        try:\n";
+    file.oss << pyx_resolveOverloadParams(args, false, 3); // lazy: always return None even if it's a void function
 
     /// Call cython corresponding function and return
-    file.oss << argumentList(i).pyx_convertEigenTypeAndStorageOrder("        ");
-    string ret = pyx_functionCall(cls.pxd_class_in_pyx(), pxdFuncName, i);
+    file.oss << argumentList(i).pyx_convertEigenTypeAndStorageOrder("            ");
+    string call = pyx_functionCall(cls.pxd_class_in_pyx(), pxdFuncName, i);
     if (!returnVals_[i].isVoid()) {
-      file.oss << "        cdef " << returnVals_[i].pyx_returnType()
-              << " ret = " << ret << "\n";
-      file.oss << "        return True, " << returnVals_[i].pyx_casting("ret") << "\n";
+      file.oss << "            return_value = " << call << "\n";
+      file.oss << "            return True, " << returnVals_[i].pyx_casting("return_value") << "\n";
+    } else {
+      file.oss << "            " << call << "\n";
+      file.oss << "            return True, None\n";
     }
-    else {
-      file.oss << "        " << ret << "\n";
-      file.oss << "        return True, None\n";
-    } 
-    file.oss << "\n";
+    file.oss << "        except:\n";
+    file.oss << "            return False, None\n\n";
   }
 }