diff --git a/morphisms/morphism-base/length_prefix.morphism-base b/morphisms/morphism-base/length_prefix.morphism-base
index a8c13be..a5d9bd5 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 ()
-    [~<ValueDelim '\0'> Char ~ Ascii]
---> [~<LengthPrefix x86.UInt64> Char ~ Ascii]
+    <Seq~<ValueDelim '\0'> Char ~ Ascii ~ Byte>
+--> <Seq~<LengthPrefix x86.UInt64> Char ~ Ascii ~ Byte>
 @lib/libmorph_length-prefix.so:src/length_prefix.c
 
 morph_string_as_length_prefix_to_nullterm ()
-    [~<LengthPrefix x86.UInt64> Char ~ Ascii]
---> [~<ValueDelim '\0'> Char ~ Ascii]
+    <Seq~<LengthPrefix x86.UInt64> Char ~ Ascii ~ Byte>
+--> <Seq~<ValueDelim '\0'> Char ~ Ascii ~ Byte>
 @lib/libmorph_length-prefix.so:src/length_prefix.c
diff --git a/morphisms/morphism-base/posint.morphism-base b/morphisms/morphism-base/posint.morphism-base
index af1e3f1..aeb5e37 100644
--- a/morphisms/morphism-base/posint.morphism-base
+++ b/morphisms/morphism-base/posint.morphism-base
@@ -11,26 +11,26 @@ morph_digit_as_uint8_to_char (Radix:ℤ_16)
 morph_posint_radix (SrcRadix:ℤ, DstRadix:ℤ)
       ℕ
     ~ <PosInt SrcRadix LittleEndian>
-    ~ [~<LengthPrefix x86.UInt64> <Digit SrcRadix>~x86.UInt64]
+    ~ <Seq~<LengthPrefix x86.UInt64> <Digit SrcRadix>~x86.UInt64>
 -->   ℕ
     ~ <PosInt DstRadix LittleEndian>
-    ~ [~<LengthPrefix x86.UInt64> <Digit DstRadix>~x86.UInt64]
+    ~ <Seq~<LengthPrefix x86.UInt64> <Digit DstRadix>~x86.UInt64>
 @lib/libmorph-posint.so:src/posint.c
 
 morph_posint_endianness (Radix:ℤ)
       ℕ
     ~ <PosInt Radix LittleEndian>
-    ~ [~<LengthPrefix x86.UInt64> <Digit Radix> ~ x86.UInt64]
+    ~ <Seq~<LengthPrefix x86.UInt64> <Digit Radix> ~ x86.UInt64>
 -->   ℕ
     ~ <PosInt Radix BigEndian>
-    ~ [~<LengthPrefix x86.UInt64> <Digit Radix> ~ x86.UInt64]
+    ~ <Seq~<LengthPrefix x86.UInt64> <Digit Radix> ~ x86.UInt64>
 @lib/libmorph-posint.so:src/posint.c
 
 morph_posint_endianness (Radix:ℤ)
       ℕ
     ~ <PosInt Radix BigEndian>
-    ~ [~<LengthPrefix x86.UInt64> <Digit Radix> ~ x86.UInt64]
+    ~ <Seq~<LengthPrefix x86.UInt64> <Digit Radix> ~ x86.UInt64>
 -->   ℕ
     ~ <PosInt Radix LittleEndian>
-    ~ [~<LengthPrefix x86.UInt64> <Digit Radix> ~ x86.UInt64]
+    ~ <Seq~<LengthPrefix x86.UInt64> <Digit Radix> ~ x86.UInt64>
 @lib/libmorph-posint.so:src/posint.c