diff --git a/percent_encoding/lib.rs b/percent_encoding/lib.rs
index 35aadee2d..86cc863a0 100644
--- a/percent_encoding/lib.rs
+++ b/percent_encoding/lib.rs
@@ -116,6 +116,14 @@ impl EncodeSet for SIMPLE_ENCODE_SET {
     }
 }
 
+define_encode_set! {
+    /// This encode set is used in the URL parser for fragments.
+    ///
+    /// Aside from special chacters defined in the [`SIMPLE_ENCODE_SET`](struct.SIMPLE_ENCODE_SET.html),
+    /// space, double quote ("), hash (#), inequality qualifiers (<), (>), and backtick (`) are encoded.
+    pub FRAGMENT_ENCODE_SET = [SIMPLE_ENCODE_SET] | {' ', '"', '#', '<', '>', '`'}
+}
+
 define_encode_set! {
     /// This encode set is used in the URL parser for query strings.
     ///
diff --git a/src/parser.rs b/src/parser.rs
index 4f9cc524b..b447364a8 100644
--- a/src/parser.rs
+++ b/src/parser.rs
@@ -18,8 +18,8 @@ use encoding::EncodingOverride;
 use host::{Host, HostInternal};
 use percent_encoding::{
     utf8_percent_encode, percent_encode,
-    SIMPLE_ENCODE_SET, DEFAULT_ENCODE_SET, USERINFO_ENCODE_SET, QUERY_ENCODE_SET,
-    PATH_SEGMENT_ENCODE_SET
+    SIMPLE_ENCODE_SET, FRAGMENT_ENCODE_SET, DEFAULT_ENCODE_SET, USERINFO_ENCODE_SET,
+    QUERY_ENCODE_SET, PATH_SEGMENT_ENCODE_SET
 };
 
 define_encode_set! {
@@ -1198,7 +1198,7 @@ impl<'a> Parser<'a> {
             } else {
                 self.check_url_code_point(c, &input);
                 self.serialization.extend(utf8_percent_encode(utf8_c,
-                                                              SIMPLE_ENCODE_SET));
+                                                              FRAGMENT_ENCODE_SET));
             }
         }
     }
diff --git a/tests/setters_tests.json b/tests/setters_tests.json
index a45171bf3..e723b13a3 100644
--- a/tests/setters_tests.json
+++ b/tests/setters_tests.json
@@ -1483,8 +1483,8 @@
             "href": "https://example.net?lang=en-US",
             "new_value": "##nav",
             "expected": {
-                "href": "https://example.net/?lang=en-US##nav",
-                "hash": "##nav"
+                "href": "https://example.net/?lang=en-US#%23nav",
+                "hash": "#%23nav"
             }
         },
         {
@@ -1512,12 +1512,12 @@
             }
         },
         {
-            "comment": "Simple percent-encoding; nuls, tabs, and newlines are removed",
+            "comment": "Fragment percent-encoding; nuls, tabs, spaces, double quotes, backticks, inequality qualifiers and newlines are removed",
             "href": "a:/",
             "new_value": "\u0000\u0001\t\n\r\u001f !\u0000\u0001\t\n\r\u001f !\"#$%&'()*+,-./09:;<=>?@AZ[\\]^_`az{|}~\u007f\u0080\u0081Éé",
             "expected": {
-                "href": "a:/#!%01%1F !\"#$%&'()*+,-./09:;<=>?@AZ[\\]^_`az{|}~%7F%C2%80%C2%81%C3%89%C3%A9",
-                "hash": "#!%01%1F !\"#$%&'()*+,-./09:;<=>?@AZ[\\]^_`az{|}~%7F%C2%80%C2%81%C3%89%C3%A9"
+                "href": "a:/#!%01%1F%20!%22%23$%&'()*+,-./09:;%3C=%3E?@AZ[\\]^_%60az{|}~%7F%C2%80%C2%81%C3%89%C3%A9",
+                "hash": "#!%01%1F%20!%22%23$%&'()*+,-./09:;%3C=%3E?@AZ[\\]^_%60az{|}~%7F%C2%80%C2%81%C3%89%C3%A9"
             }
         },
         {
diff --git a/tests/urltestdata.json b/tests/urltestdata.json
index 5565c938f..0bc22f1ba 100644
--- a/tests/urltestdata.json
+++ b/tests/urltestdata.json
@@ -153,7 +153,7 @@
   {
     "input": "http://f:21/ b ? d # e ",
     "base": "http://example.org/foo/bar",
-    "href": "http://f:21/%20b%20?%20d%20# e",
+    "href": "http://f:21/%20b%20?%20d%20#%20e",
     "origin": "http://f:21",
     "protocol": "http:",
     "username": "",
@@ -163,12 +163,12 @@
     "port": "21",
     "pathname": "/%20b%20",
     "search": "?%20d%20",
-    "hash": "# e"
+    "hash": "#%20e"
   },
   {
     "input": "lolscheme:x x#x x",
     "base": "about:blank",
-    "href": "lolscheme:x x#x x",
+    "href": "lolscheme:x x#x%20x",
     "protocol": "lolscheme:",
     "username": "",
     "password": "",
@@ -177,7 +177,7 @@
     "port": "",
     "pathname": "x x",
     "search": "",
-    "hash": "#x x"
+    "hash": "#x%20x"
   },
   {
     "input": "http://f:/c",
@@ -812,7 +812,7 @@
   {
     "input": "http://foo/path;a??e#f#g",
     "base": "http://example.org/foo/bar",
-    "href": "http://foo/path;a??e#f#g",
+    "href": "http://foo/path;a??e#f%23g",
     "origin": "http://foo",
     "protocol": "http:",
     "username": "",
@@ -822,7 +822,7 @@
     "port": "",
     "pathname": "/path;a",
     "search": "??e",
-    "hash": "#f#g"
+    "hash": "#f%23g"
   },
   {
     "input": "http://foo/abcd?efgh?ijkl",
@@ -2260,7 +2260,7 @@
   {
     "input": "http://www.google.com/foo?bar=baz# »",
     "base": "about:blank",
-    "href": "http://www.google.com/foo?bar=baz# %C2%BB",
+    "href": "http://www.google.com/foo?bar=baz#%20%C2%BB",
     "origin": "http://www.google.com",
     "protocol": "http:",
     "username": "",
@@ -2270,12 +2270,12 @@
     "port": "",
     "pathname": "/foo",
     "search": "?bar=baz",
-    "hash": "# %C2%BB"
+    "hash": "#%20%C2%BB"
   },
   {
     "input": "data:test# »",
     "base": "about:blank",
-    "href": "data:test# %C2%BB",
+    "href": "data:test#%20%C2%BB",
     "origin": "null",
     "protocol": "data:",
     "username": "",
@@ -2285,7 +2285,7 @@
     "port": "",
     "pathname": "test",
     "search": "",
-    "hash": "# %C2%BB"
+    "hash": "#%20%C2%BB"
   },
   {
     "input": "http://www.google.com",