diff --git a/morphisms/morphism-base/length_prefix.morphism-base b/morphisms/morphism-base/length_prefix.morphism-base
index a5d9bd5..290f212 100644
--- a/morphisms/morphism-base/length_prefix.morphism-base
+++ b/morphisms/morphism-base/length_prefix.morphism-base
@@ -1,9 +1,9 @@
 morph_string_as_nullterm_to_length_prefix ()
-    <Seq~<ValueDelim '\0'> Char ~ Ascii ~ Byte>
---> <Seq~<LengthPrefix x86.UInt64> Char ~ Ascii ~ Byte>
+    <Seq~<ValueDelim '\0'> x86.UInt8>
+--> <Seq~<LengthPrefix x86.UInt64> x86.UInt8>
 @lib/libmorph_length-prefix.so:src/length_prefix.c
 
 morph_string_as_length_prefix_to_nullterm ()
-    <Seq~<LengthPrefix x86.UInt64> Char ~ Ascii ~ Byte>
---> <Seq~<ValueDelim '\0'> Char ~ Ascii ~ Byte>
+    <Seq~<LengthPrefix x86.UInt64> x86.UInt8>
+--> <Seq~<ValueDelim '\0'> x86.UInt8>
 @lib/libmorph_length-prefix.so:src/length_prefix.c