Index: generic/gentclAPI.decls
===================================================================
diff -u -rcd12f5a50d870605292d8c957cb2a079f1a17c10 -r496ffe8fb5e5bdaba56fe3a939d32634bdbcb088
--- generic/gentclAPI.decls	(.../gentclAPI.decls)	(revision cd12f5a50d870605292d8c957cb2a079f1a17c10)
+++ generic/gentclAPI.decls	(.../gentclAPI.decls)	(revision 496ffe8fb5e5bdaba56fe3a939d32634bdbcb088)
@@ -140,6 +140,7 @@
 }
 xotclCmd valuecheck XOTclValuecheckCmd {
   {-argName "param" -type tclobj}
+  {-argName "-nocomplain"}
   {-argName "value" -required 0 -type tclobj}
 }
 #
Index: generic/tclAPI.h
===================================================================
diff -u -rcd12f5a50d870605292d8c957cb2a079f1a17c10 -r496ffe8fb5e5bdaba56fe3a939d32634bdbcb088
--- generic/tclAPI.h	(.../tclAPI.h)	(revision cd12f5a50d870605292d8c957cb2a079f1a17c10)
+++ generic/tclAPI.h	(.../tclAPI.h)	(revision 496ffe8fb5e5bdaba56fe3a939d32634bdbcb088)
@@ -283,7 +283,7 @@
 static int XOTclRelationCmd(Tcl_Interp *interp, XOTclObject *object, int relationtype, Tcl_Obj *value);
 static int XOTclSetInstvarCmd(Tcl_Interp *interp, XOTclObject *object, Tcl_Obj *variable, Tcl_Obj *value);
 static int XOTclSetterCmd(Tcl_Interp *interp, XOTclObject *object, int withPer_object, Tcl_Obj *parameter);
-static int XOTclValuecheckCmd(Tcl_Interp *interp, Tcl_Obj *param, Tcl_Obj *value);
+static int XOTclValuecheckCmd(Tcl_Interp *interp, Tcl_Obj *param, int withNocomplain, Tcl_Obj *value);
 
 enum {
  XOTclCAllocMethodIdx,
@@ -1947,10 +1947,11 @@
     return TCL_ERROR;
   } else {
     Tcl_Obj *param = (Tcl_Obj *)pc.clientData[0];
-    Tcl_Obj *value = (Tcl_Obj *)pc.clientData[1];
+    int withNocomplain = (int )PTR2INT(pc.clientData[1]);
+    Tcl_Obj *value = (Tcl_Obj *)pc.clientData[2];
 
     parseContextRelease(&pc);
-    return XOTclValuecheckCmd(interp, param, value);
+    return XOTclValuecheckCmd(interp, param, withNocomplain, value);
 
   }
 }
@@ -2309,8 +2310,9 @@
   {"-per-object", 0, 0, convertToString},
   {"parameter", 0, 0, convertToTclobj}}
 },
-{"::xotcl::valuecheck", XOTclValuecheckCmdStub, 2, {
+{"::xotcl::valuecheck", XOTclValuecheckCmdStub, 3, {
   {"param", 0, 0, convertToTclobj},
+  {"-nocomplain", 0, 0, convertToString},
   {"value", 0, 0, convertToTclobj}}
 },{NULL}
 };
Index: generic/xotcl.c
===================================================================
diff -u -r782f6b060b16282799fe936bc528f512e562362a -r496ffe8fb5e5bdaba56fe3a939d32634bdbcb088
--- generic/xotcl.c	(.../xotcl.c)	(revision 782f6b060b16282799fe936bc528f512e562362a)
+++ generic/xotcl.c	(.../xotcl.c)	(revision 496ffe8fb5e5bdaba56fe3a939d32634bdbcb088)
@@ -6219,7 +6219,6 @@
       Tcl_GetIntFromObj(interp, Tcl_GetObjResult(interp), &success);
       if (success == 1) {
 	*clientData = (ClientData)objPtr;
-	*outObjPtr = objPtr;
       } else {
 	result = XOTclVarErrMsg(interp, "expected ", ObjStr(pPtr->converterArg), 
 				" but got \"", ObjStr(objPtr), 
@@ -6228,9 +6227,9 @@
     }
   } else {
     *clientData = (ClientData)objPtr;
-    *outObjPtr = objPtr;
     result = TCL_OK;
   }
+  *outObjPtr = objPtr;
   return result;
 }
 
@@ -6347,6 +6346,8 @@
       ObjStr(objPtr), ObjStr(Tcl_GetObjResult(interp)));*/
     *outObjPtr = Tcl_GetObjResult(interp);
     *clientData = (ClientData) *outObjPtr;
+  } else {
+    *outObjPtr = objPtr; /* xxx */
   }
   return result;
 }
@@ -9679,6 +9680,7 @@
       DECR_REF_COUNT(resultObj);
       DECR_REF_COUNT(*outObjPtr);
       *flags &= ~XOTCL_PC_MUST_DECR;
+      *outObjPtr = objPtr;
       break;
     }
   }
@@ -12450,9 +12452,11 @@
 /*
 xotclCmd valuecheck XOTclValuecheckCmd {
   {-argName "param" -type tclobj}
+  {-argName "-nocomplain"}
   {-argName "value" -required 0 -type tclobj}
-  } */
-static int XOTclValuecheckCmd(Tcl_Interp *interp, Tcl_Obj *objPtr, Tcl_Obj *value) {
+  } 
+*/
+static int XOTclValuecheckCmd(Tcl_Interp *interp, Tcl_Obj *objPtr, int withNocomplain, Tcl_Obj *value) {
   ClientData checkedData;
   XOTclParam *paramPtr;
   Tcl_Obj *outObjPtr;
@@ -12474,16 +12478,22 @@
   result = ArgumentCheck(interp, value, paramPtr, &flags, &checkedData, &outObjPtr);
 
   if (value != outObjPtr) {
+    fprintf(stderr, "reset result %p %p\n", value, outObjPtr);
     Tcl_ResetResult(interp);
   }
 
   if (flags & XOTCL_PC_MUST_DECR) {
     DECR_REF_COUNT(outObjPtr);
   }
 
-  Tcl_SetIntObj(Tcl_GetObjResult(interp), (result == TCL_OK));
+  if (withNocomplain) {
+    Tcl_SetIntObj(Tcl_GetObjResult(interp), (result == TCL_OK));
+    result = TCL_OK;
+  } else if (result == TCL_OK) {
+    Tcl_SetIntObj(Tcl_GetObjResult(interp), 1);
+  }
 
-  return TCL_OK;
+  return result;
 }
 
 /***************************
Index: tests/parameters.xotcl
===================================================================
diff -u -rca751243a48ebff49bf1a105830e4c0d6d3961ba -r496ffe8fb5e5bdaba56fe3a939d32634bdbcb088
--- tests/parameters.xotcl	(.../parameters.xotcl)	(revision ca751243a48ebff49bf1a105830e4c0d6d3961ba)
+++ tests/parameters.xotcl	(.../parameters.xotcl)	(revision 496ffe8fb5e5bdaba56fe3a939d32634bdbcb088)
@@ -19,23 +19,29 @@
 
 ? {::xotcl::valuecheck object o1} 1
 ? {::xotcl::is o1 object} 1
-? {::xotcl::valuecheck class o1} 0
+? {::xotcl::valuecheck class o1} {expected class but got "o1" for parameter value}
+? {::xotcl::valuecheck class -nocomplain o1} 0
 ? {::xotcl::valuecheck class Test} 1
 ? {::xotcl::valuecheck object,multivalued [list o1 Test]} 1
 ? {::xotcl::valuecheck integer 1} 1
 ? {::xotcl::valuecheck integer,multivalued [list 1 2 3]} 1
-? {::xotcl::valuecheck integer,multivalued [list 1 2 3 a]} 0
+? {::xotcl::valuecheck integer,multivalued [list 1 2 3 a]} \
+    {invalid value in "1 2 3 a": expected integer but got "a" for parameter value}
 ? {::xotcl::valuecheck object,type=::C c1} 1
-? {::xotcl::valuecheck object,type=::C o} 0 "object, but different type"
-? {::xotcl::valuecheck object,type=::C c} 0 "no object"
+? {::xotcl::valuecheck object,type=::C o} \
+    {expected object but got "o" for parameter value} \
+    "object, but different type"
+? {::xotcl::valuecheck object,type=::C c} \
+    {expected object but got "c" for parameter value} \
+    "no object"
 ? {::xotcl::valuecheck object,type=::xotcl2::Object c1} 1 "general type"
 
 # do not allow "currently unknown" user defined types in valuecheck
 ? {::xotcl::valuecheck in1 aaa} {invalid value constraints "in1"}
 
 ? {::xotcl::valuecheck lower c} 1 "lower case char"
 ? {::xotcl::valuecheck lower abc} 1 "lower case chars"
-? {::xotcl::valuecheck lower Abc} 0 "no lower case chars"
+? {::xotcl::valuecheck lower Abc} {expected lower but got "Abc" for parameter value} "no lower case chars"
 ? {string is lower abc} 1 "tcl command 'string is lower'"
 
 ? {::xotcl::valuecheck {i:integer 1} 2} {invalid value constraints "i:integer 1"}
@@ -760,15 +766,19 @@
 Object create tmpObj
 tmpObj method type=mType {name value arg:optional} {
   if {$value} {
-    error invalid
+    error "expected false but got $value"
   }
   # Note that this converter does NOT return a value; it converts all
   # values into emtpy strings.
 }
 
-? {::xotcl::valuecheck mType,slot=::tmpObj,multivalued {1 0}} 0 "fail on first value"
+? {::xotcl::valuecheck mType,slot=::tmpObj,multivalued {1 0}} \
+    {invalid value in "1 0": expected false but got 1} \
+    "fail on first value"
 ? {::xotcl::valuecheck mType,slot=::tmpObj,multivalued {0 0 0}} 1 "all pass"
-? {::xotcl::valuecheck mType,slot=::tmpObj,multivalued {0 1}} 0 "fail o last value"
+? {::xotcl::valuecheck mType,slot=::tmpObj,multivalued {0 1}} \
+    {invalid value in "0 1": expected false but got 1} \
+    "fail o last value"
 
 #######################################################
 # slot specific converter