diff --git a/src/backend/utils/adt/encode.c b/src/backend/utils/adt/encode.c
index 4a6fcb56cd..8b059bc834 100644
--- a/src/backend/utils/adt/encode.c
+++ b/src/backend/utils/adt/encode.c
@@ -145,7 +145,7 @@ binary_decode(PG_FUNCTION_ARGS)
  * HEX
  */
 
-static const char hextbl[] = "0123456789abcdef";
+static const char hextbl[512] = "000102030405060708090a0b0c0d0e0f101112131415161718191a1b1c1d1e1f202122232425262728292a2b2c2d2e2f303132333435363738393a3b3c3d3e3f404142434445464748494a4b4c4d4e4f505152535455565758595a5b5c5d5e5f606162636465666768696a6b6c6d6e6f707172737475767778797a7b7c7d7e7f808182838485868788898a8b8c8d8e8f909192939495969798999a9b9c9d9e9fa0a1a2a3a4a5a6a7a8a9aaabacadaeafb0b1b2b3b4b5b6b7b8b9babbbcbdbebfc0c1c2c3c4c5c6c7c8c9cacbcccdcecfd0d1d2d3d4d5d6d7d8d9dadbdcdddedfe0e1e2e3e4e5e6e7e8e9eaebecedeeeff0f1f2f3f4f5f6f7f8f9fafbfcfdfeff";
 
 static const int8 hexlookup[128] = {
 	-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
@@ -165,9 +165,8 @@ hex_encode(const char *src, size_t len, char *dst)
 
 	while (src < end)
 	{
-		*dst++ = hextbl[(*src >> 4) & 0xF];
-		*dst++ = hextbl[*src & 0xF];
-		src++;
+		memcpy(dst, &hextbl[(* ((unsigned char *) src)) * 2], 2);
+		src++; dst+=2;
 	}
 	return (uint64) len * 2;
 }