diff --git a/wrap/Argument.cpp b/wrap/Argument.cpp
index 07f68a11d..062b7b120 100644
--- a/wrap/Argument.cpp
+++ b/wrap/Argument.cpp
@@ -25,6 +25,13 @@
 using namespace std;
 using namespace wrap;
 
+/* ************************************************************************* */
+string Argument::matlabClass() const {
+	if (type=="Vector") return string("double");
+	if (type=="Matrix") return string("double");
+	return type;
+}
+
 /* ************************************************************************* */
 void Argument::matlab_unwrap(ofstream& ofs, const string& matlabName) const {
   ofs << "  ";
@@ -62,7 +69,7 @@ string Argument::qualifiedType(const string& delim) const {
 string ArgumentList::types() const {
   string str;
   bool first=true;
-  BOOST_FOREACH(Argument arg, *this)  {
+  BOOST_FOREACH(Argument arg, *this) {
     if (!first) str += ","; str += arg.type; first=false;
   }
   return str;
@@ -73,20 +80,14 @@ string ArgumentList::signature() const {
   string sig;
   bool cap=false;
 
-  BOOST_FOREACH(Argument arg, *this)
-  {
-
+  BOOST_FOREACH(Argument arg, *this) {
   	BOOST_FOREACH(char ch, arg.type)
-        if(isupper(ch))
-        {
+        if(isupper(ch)) {
             sig += ch;
-            //If there is a capital letter, we don't want to readd it below
+            //If there is a capital letter, we don't want to read it below
             cap=true;
         }
-
-    if(!cap)
-        sig += arg.type[0];
-
+    if(!cap) sig += arg.type[0];
     //Reset to default
     cap = false;
   }
diff --git a/wrap/Argument.h b/wrap/Argument.h
index cb5b1b8c8..9b9bd6bfb 100644
--- a/wrap/Argument.h
+++ b/wrap/Argument.h
@@ -28,21 +28,31 @@ struct Argument {
 	std::string type;
 	std::string name;
 	std::vector<std::string> namespaces;
+
 	Argument() :
 			is_const(false), is_ref(false), is_ptr(false) {
 	}
 
-	std::string qualifiedType(const std::string& delim = "") const; // adds namespaces to type
+	/// return MATLAB class for use in isa(x,class)
+	std::string matlabClass() const;
+
+	/// adds namespaces to type
+	std::string qualifiedType(const std::string& delim = "") const;
 
 	/// MATLAB code generation, MATLAB to C++
 	void matlab_unwrap(std::ofstream& ofs, const std::string& matlabName) const;
 };
 
-/// Argument list
+/// Argument list is just a container with Arguments
 struct ArgumentList: public std::vector<Argument> {
-	std::vector<Argument> args; // why does it contain this?
+
+	/// create a comma-separated string listing all argument types (not used)
 	std::string types() const;
+
+	/// create a short "signature" string
 	std::string signature() const;
+
+	/// create a comma-separated string listing all argument names, used in m-files
 	std::string names() const;
 
 	// MATLAB code generation:
diff --git a/wrap/Constructor.cpp b/wrap/Constructor.cpp
index a822f722f..3f08a6f2a 100644
--- a/wrap/Constructor.cpp
+++ b/wrap/Constructor.cpp
@@ -33,10 +33,22 @@ string Constructor::matlab_wrapper_name(const string& className) const {
 
 /* ************************************************************************* */
 void Constructor::matlab_proxy_fragment(ofstream& ofs, const string& className) const {
-  ofs << "      if nargin == " << args.size() << ", obj.self = " 
-      << matlab_wrapper_name(className) << "(";
+	size_t nrArgs = args.size();
+	// check for number of arguments...
+  ofs << "      if (nargin == " << nrArgs;
+  if (nrArgs>0) ofs << " & ";
+	// ...and their types
   bool first = true;
-  for(size_t i=0;i<args.size();i++) {
+  for(size_t i=0;i<nrArgs;i++) {
+    if (!first) ofs << " & ";
+    ofs << "isa(varargin{" << i+1 << "},'" << args[i].matlabClass() << "')";
+    first=false;
+  }
+  // emit code for calling constructor
+  ofs << "), obj.self = " << matlab_wrapper_name(className) << "(";
+  // emit constructor arguments
+  first = true;
+  for(size_t i=0;i<nrArgs;i++) {
     if (!first) ofs << ",";
     ofs << "varargin{" << i+1 << "}";
     first=false;
diff --git a/wrap/Constructor.h b/wrap/Constructor.h
index b9a44e2cc..d1b85295f 100644
--- a/wrap/Constructor.h
+++ b/wrap/Constructor.h
@@ -44,7 +44,10 @@ struct Constructor {
 	/// wrapper name
 	std::string matlab_wrapper_name(const std::string& className) const;
 
-	/// proxy class fragment
+	/**
+	 * Create fragment to select constructor in proxy class, e.g.,
+	 * if nargin == 2, obj.self = new_Pose3_RP(varargin{1},varargin{2}); end
+	 */
 	void matlab_proxy_fragment(std::ofstream& ofs, const std::string& className) const;
 
 	/// m-file
diff --git a/wrap/tests/expected/@Point2/Point2.m b/wrap/tests/expected/@Point2/Point2.m
index c16d76524..f5d177933 100644
--- a/wrap/tests/expected/@Point2/Point2.m
+++ b/wrap/tests/expected/@Point2/Point2.m
@@ -4,8 +4,8 @@ classdef Point2
   end
   methods
     function obj = Point2(varargin)
-      if nargin == 0, obj.self = new_Point2_(); end
-      if nargin == 2, obj.self = new_Point2_dd(varargin{1},varargin{2}); end
+      if (nargin == 0), obj.self = new_Point2_(); end
+      if (nargin == 2 & isa(varargin{1},'double') & isa(varargin{2},'double')), obj.self = new_Point2_dd(varargin{1},varargin{2}); end
       if nargin ~= 13 && obj.self == 0, error('Point2 constructor failed'); end
     end
     function display(obj), obj.print(''); end
diff --git a/wrap/tests/expected/@Point3/Point3.m b/wrap/tests/expected/@Point3/Point3.m
index e1c277a9c..dd0dbfdfc 100644
--- a/wrap/tests/expected/@Point3/Point3.m
+++ b/wrap/tests/expected/@Point3/Point3.m
@@ -4,7 +4,7 @@ classdef Point3
   end
   methods
     function obj = Point3(varargin)
-      if nargin == 3, obj.self = new_Point3_ddd(varargin{1},varargin{2},varargin{3}); end
+      if (nargin == 3 & isa(varargin{1},'double') & isa(varargin{2},'double') & isa(varargin{3},'double')), obj.self = new_Point3_ddd(varargin{1},varargin{2},varargin{3}); end
       if nargin ~= 13 && obj.self == 0, error('Point3 constructor failed'); end
     end
     function display(obj), obj.print(''); end
diff --git a/wrap/tests/expected/@Test/Test.m b/wrap/tests/expected/@Test/Test.m
index 8574a0882..694c87014 100644
--- a/wrap/tests/expected/@Test/Test.m
+++ b/wrap/tests/expected/@Test/Test.m
@@ -4,8 +4,8 @@ classdef Test
   end
   methods
     function obj = Test(varargin)
-      if nargin == 0, obj.self = new_Test_(); end
-      if nargin == 2, obj.self = new_Test_dM(varargin{1},varargin{2}); end
+      if (nargin == 0), obj.self = new_Test_(); end
+      if (nargin == 2 & isa(varargin{1},'double') & isa(varargin{2},'double')), obj.self = new_Test_dM(varargin{1},varargin{2}); end
       if nargin ~= 13 && obj.self == 0, error('Test constructor failed'); end
     end
     function display(obj), obj.print(''); end
diff --git a/wrap/tests/expected_namespaces/@ns1ClassA/ns1ClassA.m b/wrap/tests/expected_namespaces/@ns1ClassA/ns1ClassA.m
index f5de15c80..1b05165b5 100644
--- a/wrap/tests/expected_namespaces/@ns1ClassA/ns1ClassA.m
+++ b/wrap/tests/expected_namespaces/@ns1ClassA/ns1ClassA.m
@@ -4,7 +4,7 @@ classdef ns1ClassA
   end
   methods
     function obj = ns1ClassA(varargin)
-      if nargin == 0, obj.self = new_ns1ClassA_(); end
+      if (nargin == 0), obj.self = new_ns1ClassA_(); end
       if nargin ~= 13 && obj.self == 0, error('ns1ClassA constructor failed'); end
     end
     function display(obj), obj.print(''); end
diff --git a/wrap/tests/expected_namespaces/@ns1ClassB/ns1ClassB.m b/wrap/tests/expected_namespaces/@ns1ClassB/ns1ClassB.m
index 189dab25b..78313677b 100644
--- a/wrap/tests/expected_namespaces/@ns1ClassB/ns1ClassB.m
+++ b/wrap/tests/expected_namespaces/@ns1ClassB/ns1ClassB.m
@@ -4,7 +4,7 @@ classdef ns1ClassB
   end
   methods
     function obj = ns1ClassB(varargin)
-      if nargin == 0, obj.self = new_ns1ClassB_(); end
+      if (nargin == 0), obj.self = new_ns1ClassB_(); end
       if nargin ~= 13 && obj.self == 0, error('ns1ClassB constructor failed'); end
     end
     function display(obj), obj.print(''); end
diff --git a/wrap/tests/expected_namespaces/@ns2ClassA/ns2ClassA.m b/wrap/tests/expected_namespaces/@ns2ClassA/ns2ClassA.m
index f0521377e..2718d4cf1 100644
--- a/wrap/tests/expected_namespaces/@ns2ClassA/ns2ClassA.m
+++ b/wrap/tests/expected_namespaces/@ns2ClassA/ns2ClassA.m
@@ -4,7 +4,7 @@ classdef ns2ClassA
   end
   methods
     function obj = ns2ClassA(varargin)
-      if nargin == 0, obj.self = new_ns2ClassA_(); end
+      if (nargin == 0), obj.self = new_ns2ClassA_(); end
       if nargin ~= 13 && obj.self == 0, error('ns2ClassA constructor failed'); end
     end
     function display(obj), obj.print(''); end
diff --git a/wrap/tests/expected_namespaces/@ns2ClassC/ns2ClassC.m b/wrap/tests/expected_namespaces/@ns2ClassC/ns2ClassC.m
index 78fc02073..039f5add3 100644
--- a/wrap/tests/expected_namespaces/@ns2ClassC/ns2ClassC.m
+++ b/wrap/tests/expected_namespaces/@ns2ClassC/ns2ClassC.m
@@ -4,7 +4,7 @@ classdef ns2ClassC
   end
   methods
     function obj = ns2ClassC(varargin)
-      if nargin == 0, obj.self = new_ns2ClassC_(); end
+      if (nargin == 0), obj.self = new_ns2ClassC_(); end
       if nargin ~= 13 && obj.self == 0, error('ns2ClassC constructor failed'); end
     end
     function display(obj), obj.print(''); end
diff --git a/wrap/tests/expected_namespaces/@ns2ns3ClassB/ns2ns3ClassB.m b/wrap/tests/expected_namespaces/@ns2ns3ClassB/ns2ns3ClassB.m
index 35891c5a7..154c89d48 100644
--- a/wrap/tests/expected_namespaces/@ns2ns3ClassB/ns2ns3ClassB.m
+++ b/wrap/tests/expected_namespaces/@ns2ns3ClassB/ns2ns3ClassB.m
@@ -4,7 +4,7 @@ classdef ns2ns3ClassB
   end
   methods
     function obj = ns2ns3ClassB(varargin)
-      if nargin == 0, obj.self = new_ns2ns3ClassB_(); end
+      if (nargin == 0), obj.self = new_ns2ns3ClassB_(); end
       if nargin ~= 13 && obj.self == 0, error('ns2ns3ClassB constructor failed'); end
     end
     function display(obj), obj.print(''); end