diff --git a/make_encode_sets.py b/make_encode_sets.py
index eb859050..9331b6bf 100644
--- a/make_encode_sets.py
+++ b/make_encode_sets.py
@@ -30,6 +30,7 @@
     ('USERNAME', r''' "#<>`?{}@\/:'''),
     ('FORM_URLENCODED', r''' !"#$%&\'()+,/:;<=>?@[\]^`{|}~'''),
     ('HTTP_VALUE', r''' "%'()*,/:;<->?[\]{}'''),
+    ('UNRESERVED', r''' !"#$%&\'*()+,/:;<=>?@[\]^`{|}'''),
 ]:
     print(
         "pub static %s: [&'static str; 256] = [\n%s\n];\n\n"
diff --git a/src/encode_sets.rs b/src/encode_sets.rs
index d7b5fb9d..f1cfb977 100644
--- a/src/encode_sets.rs
+++ b/src/encode_sets.rs
@@ -296,3 +296,39 @@ pub static HTTP_VALUE: [&'static str; 256] = [
 ];
 
 
+pub static UNRESERVED: [&'static str; 256] = [
+   "%00", "%01", "%02", "%03", "%04", "%05", "%06", "%07",
+   "%08", "%09", "%0A", "%0B", "%0C", "%0D", "%0E", "%0F",
+   "%10", "%11", "%12", "%13", "%14", "%15", "%16", "%17",
+   "%18", "%19", "%1A", "%1B", "%1C", "%1D", "%1E", "%1F",
+   "%20", "%21", "%22", "%23", "%24", "%25", "%26", "%27",
+   "%28", "%29", "%2A", "%2B", "%2C", "-", ".", "%2F",
+   "0", "1", "2", "3", "4", "5", "6", "7",
+   "8", "9", "%3A", "%3B", "%3C", "%3D", "%3E", "%3F",
+   "%40", "A", "B", "C", "D", "E", "F", "G",
+   "H", "I", "J", "K", "L", "M", "N", "O",
+   "P", "Q", "R", "S", "T", "U", "V", "W",
+   "X", "Y", "Z", "%5B", "%5C", "%5D", "%5E", "_",
+   "%60", "a", "b", "c", "d", "e", "f", "g",
+   "h", "i", "j", "k", "l", "m", "n", "o",
+   "p", "q", "r", "s", "t", "u", "v", "w",
+   "x", "y", "z", "%7B", "%7C", "%7D", "~", "%7F",
+   "%80", "%81", "%82", "%83", "%84", "%85", "%86", "%87",
+   "%88", "%89", "%8A", "%8B", "%8C", "%8D", "%8E", "%8F",
+   "%90", "%91", "%92", "%93", "%94", "%95", "%96", "%97",
+   "%98", "%99", "%9A", "%9B", "%9C", "%9D", "%9E", "%9F",
+   "%A0", "%A1", "%A2", "%A3", "%A4", "%A5", "%A6", "%A7",
+   "%A8", "%A9", "%AA", "%AB", "%AC", "%AD", "%AE", "%AF",
+   "%B0", "%B1", "%B2", "%B3", "%B4", "%B5", "%B6", "%B7",
+   "%B8", "%B9", "%BA", "%BB", "%BC", "%BD", "%BE", "%BF",
+   "%C0", "%C1", "%C2", "%C3", "%C4", "%C5", "%C6", "%C7",
+   "%C8", "%C9", "%CA", "%CB", "%CC", "%CD", "%CE", "%CF",
+   "%D0", "%D1", "%D2", "%D3", "%D4", "%D5", "%D6", "%D7",
+   "%D8", "%D9", "%DA", "%DB", "%DC", "%DD", "%DE", "%DF",
+   "%E0", "%E1", "%E2", "%E3", "%E4", "%E5", "%E6", "%E7",
+   "%E8", "%E9", "%EA", "%EB", "%EC", "%ED", "%EE", "%EF",
+   "%F0", "%F1", "%F2", "%F3", "%F4", "%F5", "%F6", "%F7",
+   "%F8", "%F9", "%FA", "%FB", "%FC", "%FD", "%FE", "%FF",
+];
+
+
diff --git a/src/percent_encoding.rs b/src/percent_encoding.rs
index 146bede2..903e0cac 100644
--- a/src/percent_encoding.rs
+++ b/src/percent_encoding.rs
@@ -59,6 +59,11 @@ pub static FORM_URLENCODED_ENCODE_SET: EncodeSet = EncodeSet {
 /// https://tools.ietf.org/html/rfc5987#section-3.2
 pub static HTTP_VALUE_ENCODE_SET: EncodeSet = EncodeSet { map: &encode_sets::HTTP_VALUE };
 
+/// This encode set is used for URI normalization and to implement other RFCs which rely on `unreserved`.
+pub static UNRESERVED_ENCODE_SET: EncodeSet = EncodeSet {
+    map: &encode_sets::UNRESERVED,
+};
+
 /// Percent-encode the given bytes, and push the result to `output`.
 ///
 /// The pushed strings are within the ASCII range.