diff --git a/compiler/defutil.pas b/compiler/defutil.pas
index db47490007..9f7dd87ffa 100644
--- a/compiler/defutil.pas
+++ b/compiler/defutil.pas
@@ -1047,7 +1047,7 @@ implementation
           floatdef:
             result:=tfloatdef(p).floattype in [s64currency,s64real,s32real];
           stringdef:
-            result:=tstringdef(p).stringtype in [st_ansistring,st_widestring];
+            result:=tstringdef(p).stringtype in [st_ansistring,st_widestring,st_unicodestring];
           variantdef:
             result:=true;
           objectdef:
diff --git a/compiler/ncal.pas b/compiler/ncal.pas
index 2ed18366d9..d464bc6fc7 100644
--- a/compiler/ncal.pas
+++ b/compiler/ncal.pas
@@ -400,7 +400,7 @@ implementation
 
             { we've to know the parameter size to allocate the temp. space }
             is_byref_para(assignmenttype);
-            inc(paramssize, assignmenttype.size);
+            inc(paramssize,max(voidpointertype.size,assignmenttype.size));
 
             para:=tcallparanode(para.nextpara);
           end;
@@ -454,7 +454,7 @@ implementation
               restype:=restype or $80;
 
             { assign the argument/parameter to the temporary location }
-            { we always pass Variants by reference, RTL helpers must handle it
+            { for Variants, we always pass a pointer, RTL helpers must handle it
               depending on byref bit }
 
             if assignmenttype=voidpointertype then
@@ -474,7 +474,7 @@ implementation
                 )),assignmenttype),
                 ctypeconvnode.create_internal(para.left,assignmenttype)));
 
-            inc(paramssize,assignmenttype.size);
+            inc(paramssize,max(voidpointertype.size,assignmenttype.size));
             calldescnode.appendbyte(restype);
 
             para.left:=nil;