diff --git a/src/z_fm_test_data_param_value.xslt.source.xml b/src/z_fm_test_data_param_value.xslt.source.xml
new file mode 100644
index 0000000..84c02af
--- /dev/null
+++ b/src/z_fm_test_data_param_value.xslt.source.xml
@@ -0,0 +1,9 @@
+<xsl:transform xmlns:xsl="http://www.w3.org/1999/XSL/Transform" xmlns:sap="http://www.sap.com/sapxsl" version="1.0">
+
+  <xsl:strip-space elements="*"/>
+
+  <xsl:template match="/asx:abap/asx:values" xmlns:asx="http://www.sap.com/abapxml">
+    <xsl:copy-of select="ROOT"/>
+  </xsl:template>
+
+</xsl:transform>
diff --git a/src/z_fm_test_data_param_value.xslt.xml b/src/z_fm_test_data_param_value.xslt.xml
new file mode 100644
index 0000000..12c67fe
--- /dev/null
+++ b/src/z_fm_test_data_param_value.xslt.xml
@@ -0,0 +1,12 @@
+<?xml version="1.0" encoding="utf-8"?>
+<abapGit version="v1.0.0" serializer="LCL_OBJECT_XSLT" serializer_version="v1.0.0">
+ <asx:abap xmlns:asx="http://www.sap.com/abapxml" version="1.0">
+  <asx:values>
+   <ATTRIBUTES>
+    <XSLTDESC>Z_FM_TEST_DATA_PARAM_VALUE</XSLTDESC>
+    <LANGU>E</LANGU>
+    <DESCRIPT>Serialization/Deserialization of test data</DESCRIPT>
+   </ATTRIBUTES>
+  </asx:values>
+ </asx:abap>
+</abapGit>
diff --git a/src/z_fm_test_data_param_value2.xslt.source.xml b/src/z_fm_test_data_param_value2.xslt.source.xml
new file mode 100644
index 0000000..ce2b539
--- /dev/null
+++ b/src/z_fm_test_data_param_value2.xslt.source.xml
@@ -0,0 +1,15 @@
+<xsl:transform xmlns:xsl="http://www.w3.org/1999/XSL/Transform" xmlns:sap="http://www.sap.com/sapxsl" version="1.0">
+
+  <xsl:strip-space elements="*"/>
+
+  <xsl:template match="/">
+    <asx:abap xmlns:asx="http://www.sap.com/abapxml">
+      <asx:values>
+        <DATA>
+          <xsl:copy-of select="value/(*|text())"/>
+        </DATA>
+      </asx:values>
+    </asx:abap>
+  </xsl:template>
+
+</xsl:transform>
diff --git a/src/z_fm_test_data_param_value2.xslt.xml b/src/z_fm_test_data_param_value2.xslt.xml
new file mode 100644
index 0000000..56f71ba
--- /dev/null
+++ b/src/z_fm_test_data_param_value2.xslt.xml
@@ -0,0 +1,12 @@
+<?xml version="1.0" encoding="utf-8"?>
+<abapGit version="v1.0.0" serializer="LCL_OBJECT_XSLT" serializer_version="v1.0.0">
+ <asx:abap xmlns:asx="http://www.sap.com/abapxml" version="1.0">
+  <asx:values>
+   <ATTRIBUTES>
+    <XSLTDESC>Z_FM_TEST_DATA_PARAM_VALUE2</XSLTDESC>
+    <LANGU>E</LANGU>
+    <DESCRIPT>Serialization/Deserialization of test data</DESCRIPT>
+   </ATTRIBUTES>
+  </asx:values>
+ </asx:abap>
+</abapGit>
diff --git a/src/zcl_fm_test_data_apack.clas.abap b/src/zcl_fm_test_data_apack.clas.abap
index 20ecda9..090a55a 100644
--- a/src/zcl_fm_test_data_apack.clas.abap
+++ b/src/zcl_fm_test_data_apack.clas.abap
@@ -33,7 +33,7 @@ CLASS ZCL_FM_TEST_DATA_APACK IMPLEMENTATION.
               target_package = '' )
             ( group_id       = 'github.com/sandraros'
               artifact_id    = 'FM-params-RTTS'
-              version        = '0.2'
+              version        = '1.0'
               git_url        = 'https://github.com/sandraros/FM-params-RTTS.git'
               target_package = '' )
             ( group_id       = 'github.com/sandraros'
diff --git a/src/zcl_fm_test_data_serialize.clas.abap b/src/zcl_fm_test_data_serialize.clas.abap
index abc5603..8ae4327 100644
--- a/src/zcl_fm_test_data_serialize.clas.abap
+++ b/src/zcl_fm_test_data_serialize.clas.abap
@@ -78,6 +78,7 @@ CLASS zcl_fm_test_data_serialize DEFINITION
 
   PROTECTED SECTION.
   PRIVATE SECTION.
+    CLASS-DATA: params_rtts TYPE zcl_fm_params_rtts=>ty_params_rtts.
 
     CLASS-METHODS get_parameter
       IMPORTING
@@ -109,6 +110,11 @@ CLASS zcl_fm_test_data_serialize DEFINITION
         VALUE(result)   TYPE abap_func_parmbind
       RAISING
         zcx_fm_test_data.
+    CLASS-METHODS use_value_of_actual_type
+      IMPORTING
+        parameter     TYPE abap_func_parmbind
+      RETURNING
+        value(result) TYPE REF TO data.
 
 ENDCLASS.
 
@@ -119,6 +125,12 @@ CLASS zcl_fm_test_data_serialize IMPLEMENTATION.
 
   METHOD serialize.
 
+    TRY.
+        params_rtts = zcl_fm_params_rtts=>get( funcname = test_data->fm_name ).
+      CATCH zcx_fm_params_rtts.
+        RAISE EXCEPTION TYPE zcx_fm_test_data EXPORTING text = |Interface error for "{ test_data->fm_name }"|.
+    ENDTRY.
+
     DATA(serializable_test_data) = VALUE ty_test_data(
         header             = VALUE #(
                                 fm_name        = test_data->fm_name
@@ -157,6 +169,8 @@ CLASS zcl_fm_test_data_serialize IMPLEMENTATION.
         serializable_test_data-error = error->get_text( ).
     ENDTRY.
 
+    test_data_xml = replace( val = test_data_xml sub = ` asx:root="ROOT" xmlns:asx="http://www.sap.com/abapxml"` with = `` occ = 0 ).
+
   ENDMETHOD.
 
 
@@ -238,9 +252,10 @@ CLASS zcl_fm_test_data_serialize IMPLEMENTATION.
 
     " store the value
     TRY.
-        CALL TRANSFORMATION id
+        CALL TRANSFORMATION z_fm_test_data_param_value2
             SOURCE XML parameter-dynamically_defined_value
             RESULT data = <parameter_value>.
+
       CATCH cx_root INTO error.
         RAISE EXCEPTION TYPE zcx_fm_test_data EXPORTING previous = error.
     ENDTRY.
@@ -279,23 +294,29 @@ CLASS zcl_fm_test_data_serialize IMPLEMENTATION.
 
   METHOD get_parameter.
 
+    DATA: ref_parameter TYPE REF TO data,
+          error         TYPE REF TO cx_root.
     FIELD-SYMBOLS <parameter_value> TYPE any.
 
     result-name = parameter-name.
     result-kind = parameter-kind.
 
-    ASSIGN parameter-value->* TO <parameter_value>.
+    data(ref_parameter_value) = use_value_of_actual_type( parameter ).
+    ASSIGN ref_parameter_value->* TO <parameter_value>.
+
     TRY.
         " to omit the BOM, get RESULT into type XSTRING, but drawback is that it's UTF-8 to be later converted to string.
-        CALL TRANSFORMATION id
-          SOURCE data = <parameter_value>
-          RESULT XML result-dynamically_defined_value
+        CALL TRANSFORMATION z_fm_test_data_param_value
+          SOURCE root = <parameter_value>
+          RESULT XML data(XSTRING)
           OPTIONS initial_components = 'suppress' "data_refs = 'heap-or-create'
                   xml_header    = 'no'.
-      CATCH cx_root INTO DATA(error).
+      CATCH cx_root INTO error.
         RAISE EXCEPTION TYPE zcx_fm_test_data EXPORTING previous = error.
     ENDTRY.
 
+    result-dynamically_defined_value = xstring.
+
   ENDMETHOD.
 
 
@@ -305,7 +326,9 @@ CLASS zcl_fm_test_data_serialize IMPLEMENTATION.
 
     result-name = parameter-name.
 
-    ASSIGN parameter-value->* TO <parameter_value>.
+    data(ref_parameter_value) = use_value_of_actual_type( parameter ).
+    ASSIGN ref_parameter_value->* TO <parameter_value>.
+
     DATA(srtti_type) = zcl_srtti_typedescr=>create_by_data_object( <parameter_value> ).
     TRY.
         " to omit the BOM, get RESULT into type XSTRING, but drawback is that it's UTF-8 to be later converted to string.
@@ -321,4 +344,28 @@ CLASS zcl_fm_test_data_serialize IMPLEMENTATION.
   ENDMETHOD.
 
 
+  METHOD use_value_of_actual_type.
+    DATA: ref_parameter TYPE REF TO data,
+          error         TYPE REF TO cx_root.
+    FIELD-SYMBOLS <parameter_value> TYPE any.
+
+    ASSIGN parameter-value->* TO <parameter_value>.
+
+    TRY.
+        ASSIGN params_rtts[ name = parameter-name ] TO FIELD-SYMBOL(<param_rtts>).
+        IF sy-subrc = 0.
+          CREATE DATA ref_parameter TYPE HANDLE <param_rtts>-type.
+          ASSIGN ref_parameter->* TO FIELD-SYMBOL(<fm_parameter_value>).
+          <fm_parameter_value> = <parameter_value>.
+          ASSIGN <fm_parameter_value> TO <parameter_value>.
+          result = ref_parameter.
+        ELSE.
+          result = parameter-value.
+        ENDIF.
+      CATCH cx_root INTO error.
+        result = parameter-value.
+    ENDTRY.
+
+  ENDMETHOD.
+
 ENDCLASS.