diff --git a/common/locale/en-US/styling.xml b/common/locale/en-US/styling.xml
index 4aef1c1a..c5e1a04a 100644
--- a/common/locale/en-US/styling.xml
+++ b/common/locale/en-US/styling.xml
@@ -154,12 +154,22 @@
             CSS rule set (e.g., <tt>body { color: blue; }</tt>).
         </p>
 
-        <p>
-            If <a>name</a> (short option: <em>-n</em>) is provided, any existing style with the same
-            name is overridden, and the style may later be deleted using <a>name</a>. If
-            <em>-append</em> (short option: <em>-a</em>) is provided along with <em>-name</em>, <oa>css</oa> and
-            <a>filter</a> are appended to its current value.
-        </p>
+        <p>The following options are available:</p>
+        <dl>
+            <dt>-append</dt>
+            <dd>If provided along with <em>-name</em>, <oa>css</oa> and
+                <a>filter</a> are appended to its current value. (short name: <em>-a</em>)</dd>
+
+            <dt>-agent</dt>
+            <dd>If provided, the style is installed as an Agent sheet, which
+                applies to contents user interface widgets as well as normal
+                elements. (short name <em>-A</em>)</dd>
+
+            <dt>-name=<a>name</a></dt>
+            <dd>If provided, any existing style with the same name is overridden, and the style may later be deleted using <a>name</a>.
+                (short name <em>-n</em>)</dd>
+
+        </dl>
 
         <p>If <oa>css</oa> isn't provided, matching styles are listed.</p>
     </description>
diff --git a/common/modules/styles.jsm b/common/modules/styles.jsm
index 7170928e..e42ac2b3 100644
--- a/common/modules/styles.jsm
+++ b/common/modules/styles.jsm
@@ -104,8 +104,9 @@ const Styles = Module("Styles", {
             filter = filter.split(",");
         if (name && name in names) {
             var sheet = names[name];
-            sheet.sites = filter;
+            sheet.agent = agent;
             sheet.css = String(css);
+            sheet.sites = filter;
         }
         else {
             sheet = Sheet(name, this._id++, filter.filter(util.identity), String(css), system, agent);
@@ -127,7 +128,7 @@ const Styles = Module("Styles", {
      * @param {string or number} sheet The sheet to retrieve. Strings indicate
      *     sheet names, while numbers indicate indices.
      */
-    get: function getget(system, sheet) {
+    get: function get(system, sheet) {
         let sheets = system ? this.systemSheets : this.userSheets;
         let names = system ? this.systemNames : this.userNames;
         if (typeof sheet === "number")
@@ -288,7 +289,7 @@ const Styles = Module("Styles", {
                             css = sheet.css + " " + css;
                         }
                     }
-                    styles.addSheet(false, name, filter, css);
+                    styles.addSheet(false, name, filter, css, args["-agent"]);
                 }
             },
             {
@@ -307,13 +308,14 @@ const Styles = Module("Styles", {
                 hereDoc: true,
                 literal: 1,
                 options: [
+                    { names: ["-agent", "-A"],  description: "Apply style as an Agent sheet" },
+                    { names: ["-append", "-a"], description: "Append site filter and css to an existing, matching sheet" },
                     {
                         names: ["-name", "-n"],
                         description: "The name of this stylesheet",
                         completer: function () [[k, v.css] for ([k, v] in Iterator(styles.userNames))],
                         type: modules.CommandOption.STRING
-                    },
-                    { names: ["-append", "-a"], description: "Append site filter and css to an existing, matching sheet" }
+                    }
                 ],
                 serialize: function () [
                     {
diff --git a/pentadactyl/NEWS b/pentadactyl/NEWS
index 9acae799..a40b38ab 100644
--- a/pentadactyl/NEWS
+++ b/pentadactyl/NEWS
@@ -44,6 +44,7 @@
     * Added "transliterated" option to 'hintmatching'.
     * Added -javascript option to :abbrev and :map.
     * Added several new options to :map.
+    * Added -agent flag to :style
     * Removed the :source line at the end of files generated by
       :mkpentadactylrc.
     * gf now toggles between source and content view.