diff --git a/csrc/hs_hashstring_base16.c b/csrc/hs_hashstring_base16.c
--- a/csrc/hs_hashstring_base16.c
+++ b/csrc/hs_hashstring_base16.c
@@ -133,7 +133,7 @@
 // *** Main Functions ***
 // **********************
 
-int hs_hashstring_hexDecode(void *dest, const char *src, size_t srcLen)
+int hs_hashstring_hexDecode(void *restrict dest, const char *restrict src, size_t srcLen)
 {
 	int err = 0;
 
@@ -152,7 +152,7 @@
 	return err != 0;
 }
 
-int hs_hashstring_hexDecodeLower(void *dest, const char *src, size_t srcLen)
+int hs_hashstring_hexDecodeLower(void *restrict dest, const char *restrict src, size_t srcLen)
 {
 	int err = 0;
 
@@ -171,7 +171,7 @@
 	return err != 0;
 }
 
-int hs_hashstring_hexDecodeUpper(void *dest, const char *src, size_t srcLen)
+int hs_hashstring_hexDecodeUpper(void *restrict dest, const char *restrict src, size_t srcLen)
 {
 	int err = 0;
 
@@ -190,7 +190,7 @@
 	return err != 0;
 }
 
-void hs_hashstring_hexEncode(char *dest, const void *src, size_t srcLen)
+void hs_hashstring_hexEncode(char *restrict dest, const void *restrict src, size_t srcLen)
 {
 	for (size_t i = 0; i < srcLen; i++)
 	{
@@ -199,7 +199,7 @@
 	dest[2 * srcLen] = 0;
 }
 
-void hs_hashstring_hexEncodeUpper(char *dest, const void *src, size_t srcLen)
+void hs_hashstring_hexEncodeUpper(char *restrict dest, const void *restrict src, size_t srcLen)
 {
 	for (size_t i = 0; i < srcLen; i++)
 	{
diff --git a/csrc/hs_hashstring_base16.h b/csrc/hs_hashstring_base16.h
--- a/csrc/hs_hashstring_base16.h
+++ b/csrc/hs_hashstring_base16.h
@@ -23,8 +23,8 @@
 
 #include <stddef.h>
 
-int  hs_hashstring_hexDecode     (void *dest, const char *src, size_t srcLen);
-int  hs_hashstring_hexDecodeLower(void *dest, const char *src, size_t srcLen);
-int  hs_hashstring_hexDecodeUpper(void *dest, const char *src, size_t srcLen);
-void hs_hashstring_hexEncode     (char *dest, const void *src, size_t srcLen);
-void hs_hashstring_hexEncodeUpper(char *dest, const void *src, size_t srcLen);
+int  hs_hashstring_hexDecode     (void *restrict dest, const char *restrict src, size_t srcLen);
+int  hs_hashstring_hexDecodeLower(void *restrict dest, const char *restrict src, size_t srcLen);
+int  hs_hashstring_hexDecodeUpper(void *restrict dest, const char *restrict src, size_t srcLen);
+void hs_hashstring_hexEncode     (char *restrict dest, const void *restrict src, size_t srcLen);
+void hs_hashstring_hexEncodeUpper(char *restrict dest, const void *restrict src, size_t srcLen);
diff --git a/csrc/hs_hashstring_xor.c b/csrc/hs_hashstring_xor.c
--- a/csrc/hs_hashstring_xor.c
+++ b/csrc/hs_hashstring_xor.c
@@ -3,8 +3,8 @@
 
 void
 hs_hashstring_xormin
-  ( const uint8_t *const restrict a,
-    const uint8_t *const restrict b,
+  ( const uint8_t *const a,
+    const uint8_t *const b,
     const size_t len,
     uint8_t *const restrict out )
 {
@@ -15,9 +15,9 @@
 
 void
 hs_hashstring_xormax
-  ( const uint8_t *const restrict a,
+  ( const uint8_t *const a,
     const size_t alen,
-    const uint8_t *const restrict b,
+    const uint8_t *const b,
     const size_t blen,
     uint8_t *const restrict out )
 {
@@ -32,9 +32,9 @@
 
 void
 hs_hashstring_xorleft
-  ( const uint8_t *const restrict a,
+  ( const uint8_t *const a,
     const size_t alen,
-    const uint8_t *const restrict b,
+    const uint8_t *const b,
     const size_t blen,
     uint8_t *const restrict out )
 {
@@ -47,7 +47,7 @@
 }
 void
 hs_hashstring_xormutate
-  ( const uint8_t *const restrict a,
+  ( const uint8_t *const a,
     const size_t len,
     uint8_t *const restrict out )
 {
diff --git a/csrc/hs_hashstring_xor.h b/csrc/hs_hashstring_xor.h
--- a/csrc/hs_hashstring_xor.h
+++ b/csrc/hs_hashstring_xor.h
@@ -4,29 +4,29 @@
 
 void
 hs_hashstring_xormin
-  ( const uint8_t *const restrict a,
-    const uint8_t *const restrict b,
+  ( const uint8_t *const a,
+    const uint8_t *const b,
     const size_t len,
     uint8_t *const restrict out );
 
 void
 hs_hashstring_xormax
-  ( const uint8_t *const restrict a,
+  ( const uint8_t *const a,
     const size_t alen,
-    const uint8_t *const restrict b,
+    const uint8_t *const b,
     const size_t blen,
     uint8_t *const restrict out );
 
 void
 hs_hashstring_xorleft
-  ( const uint8_t *const restrict a,
+  ( const uint8_t *const a,
     const size_t alen,
-    const uint8_t *const restrict b,
+    const uint8_t *const b,
     const size_t blen,
     uint8_t *const restrict out );
 
 void
 hs_hashstring_xormutate
-  ( const uint8_t *const restrict a,
+  ( const uint8_t *const a,
     const size_t alen,
     uint8_t *const restrict out );
diff --git a/hash-string.cabal b/hash-string.cabal
--- a/hash-string.cabal
+++ b/hash-string.cabal
@@ -1,6 +1,6 @@
 cabal-version:      1.24
 name:               hash-string
-version:            0.1.0.1
+version:            0.1.0.2
 synopsis:
   binary strings supporting constant-time base16 and comparisons
 description:
@@ -41,6 +41,7 @@
                        -- csrc/hs_hashstring_base64.c
                        csrc/hs_hashstring_xor.c
 
+    cc-options: -ftree-vectorize
     default-language: Haskell2010
 
 source-repository head