diff --git a/src/token.c b/src/token.c
index f21cb86f..badbe860 100644
--- a/src/token.c
+++ b/src/token.c
@@ -416,6 +416,7 @@ const char *list_tokens(const char *s, int with_quotes)
   }
   sizetok = CADCHUNKALLOC;
   my_realloc(451, &token, sizetok);
+  token[0] = '\0';
   while(1) {
     c=*s++;
     space=SPACE(c) ;
diff --git a/src/xschem.tcl b/src/xschem.tcl
index d0a6be01..fa717d41 100644
--- a/src/xschem.tcl
+++ b/src/xschem.tcl
@@ -2420,7 +2420,7 @@ proc text_line {txtlabel clear {preserve_disabled disabled} } {
    }
    label .dialog.f1.r4 -text {   Edit Attr:}
    if  { [ info tclversion] > 8.4} {
-     ttk::combobox .dialog.f1.r5 -values $tok_list -textvariable selected_tok -width 14
+     ttk::combobox .dialog.f1.r5 -values [list $tok_list] -textvariable selected_tok -width 14
    }
 
    checkbutton .dialog.f0.l2 -text "preserve unchanged props" -variable preserve_unchanged_attrs -state $preserve_disabled