diff --git a/lib/fixed/ieee_proposed/fixed_pkg_c.patch b/lib/fixed/ieee_proposed/fixed_pkg_c.patch
new file mode 100644
index 0000000..a498d20
--- /dev/null
+++ b/lib/fixed/ieee_proposed/fixed_pkg_c.patch
@@ -0,0 +1,36 @@
+Index: fixed_pkg_c.vhdl
+===================================================================
+--- fixed_pkg_c.vhdl	(Revision 1446)
++++ fixed_pkg_c.vhdl	(Arbeitskopie)
+@@ -2266,12 +2266,13 @@
+   function to_sulv (
+     arg : UNRESOLVED_ufixed)            -- fixed point vector
+     return STD_ULOGIC_VECTOR is
+-    variable result : STD_ULOGIC_VECTOR (arg'length-1 downto 0);
++	subtype  t is STD_ULOGIC_VECTOR(arg'length-1 downto 0);
++	variable result : t;
+   begin
+     if arg'length < 1 then
+       return NSLV;
+     end if;
+-    result := STD_ULOGIC_VECTOR (arg);
++    result := To_X01(t(arg));
+     return result;
+   end function to_sulv;
+ 
+@@ -2278,12 +2279,13 @@
+   function to_sulv (
+     arg : UNRESOLVED_sfixed)            -- fixed point vector
+     return STD_ULOGIC_VECTOR is
+-    variable result : STD_ULOGIC_VECTOR (arg'length-1 downto 0);
++	subtype  t is STD_ULOGIC_VECTOR(arg'length-1 downto 0);
++	variable result : t;
+   begin
+     if arg'length < 1 then
+       return NSLV;
+     end if;
+-    result := STD_ULOGIC_VECTOR (arg);
++    result := To_X01(t(arg));
+     return result;
+   end function to_sulv;
+