diff --git a/components/style/gecko/selector_parser.rs b/components/style/gecko/selector_parser.rs
index 17650406cb1..80a8736adad 100644
--- a/components/style/gecko/selector_parser.rs
+++ b/components/style/gecko/selector_parser.rs
@@ -154,6 +154,10 @@ pub enum NonTSPseudoClass {
     ReadWrite,
     /// :read-only
     ReadOnly,
+
+    // Internal pseudo-classes
+    /// :-moz-browser-frame
+    MozBrowserFrame,
 }
 
 impl ToCss for NonTSPseudoClass {
@@ -173,6 +177,8 @@ impl ToCss for NonTSPseudoClass {
             Indeterminate => ":indeterminate",
             ReadWrite => ":read-write",
             ReadOnly => ":read-only",
+
+            MozBrowserFrame => ":-moz-browser-frame",
         })
     }
 }
@@ -196,6 +202,7 @@ impl NonTSPseudoClass {
             Indeterminate |
             ReadWrite |
             ReadOnly => false,
+            MozBrowserFrame => true,
         }
     }
 
@@ -216,7 +223,8 @@ impl NonTSPseudoClass {
 
             AnyLink |
             Link |
-            Visited => ElementState::empty(),
+            Visited |
+            MozBrowserFrame => ElementState::empty(),
         }
     }
 
@@ -236,6 +244,7 @@ impl NonTSPseudoClass {
             Disabled => disabled,
             Checked => checked,
             Indeterminate => indeterminate,
+            MozBrowserFrame => mozBrowserFrame,
             ReadWrite | ReadOnly => { return None; }
         })
     }
@@ -287,6 +296,10 @@ impl<'a> ::selectors::Parser for SelectorParser<'a> {
             "indeterminate" => Indeterminate,
             "read-write" => ReadWrite,
             "read-only" => ReadOnly,
+
+            // Internal
+            "-moz-browser-frame" => MozBrowserFrame,
+
             _ => return Err(())
         };
 
diff --git a/components/style/gecko/wrapper.rs b/components/style/gecko/wrapper.rs
index f5890e2b95f..8b74844590b 100644
--- a/components/style/gecko/wrapper.rs
+++ b/components/style/gecko/wrapper.rs
@@ -26,7 +26,7 @@ use gecko_bindings::bindings;
 use gecko_bindings::bindings::{Gecko_DropStyleChildrenIterator, Gecko_MaybeCreateStyleChildrenIterator};
 use gecko_bindings::bindings::{Gecko_ElementState, Gecko_GetLastChild, Gecko_GetNextStyleChild};
 use gecko_bindings::bindings::{Gecko_GetServoDeclarationBlock, Gecko_IsHTMLElementInHTMLDocument};
-use gecko_bindings::bindings::{Gecko_IsLink, Gecko_IsRootElement};
+use gecko_bindings::bindings::{Gecko_IsLink, Gecko_IsRootElement, Gecko_MatchesElement};
 use gecko_bindings::bindings::{Gecko_IsUnvisitedLink, Gecko_IsVisitedLink, Gecko_Namespace};
 use gecko_bindings::bindings::{Gecko_SetNodeFlags, Gecko_UnsetNodeFlags};
 use gecko_bindings::bindings::Gecko_ClassOrClassList;
@@ -519,6 +519,10 @@ impl<'le> ::selectors::Element for GeckoElement<'le> {
             NonTSPseudoClass::ReadOnly => {
                 !self.get_state().contains(pseudo_class.state_flag())
             }
+
+            NonTSPseudoClass::MozBrowserFrame => unsafe {
+                Gecko_MatchesElement(pseudo_class.to_gecko_pseudoclasstype().unwrap(), self.0)
+            }
         }
     }
 
diff --git a/components/style/gecko_bindings/bindings.rs b/components/style/gecko_bindings/bindings.rs
index d9106d9ace2..a9b73f54e8f 100644
--- a/components/style/gecko_bindings/bindings.rs
+++ b/components/style/gecko_bindings/bindings.rs
@@ -10,6 +10,7 @@ use gecko_bindings::structs::RawGeckoPresContext;
 use gecko_bindings::structs::ThreadSafeURIHolder;
 use gecko_bindings::structs::ThreadSafePrincipalHolder;
 use gecko_bindings::structs::ConsumeStyleBehavior;
+use gecko_bindings::structs::CSSPseudoClassType;
 use gecko_bindings::structs::TraversalRootBehavior;
 use gecko_bindings::structs::FontFamilyList;
 use gecko_bindings::structs::FontFamilyType;
@@ -370,6 +371,10 @@ extern "C" {
 extern "C" {
     pub fn Gecko_IsRootElement(element: RawGeckoElementBorrowed) -> bool;
 }
+extern "C" {
+    pub fn Gecko_MatchesElement(type_: CSSPseudoClassType,
+                                element: RawGeckoElementBorrowed) -> bool;
+}
 extern "C" {
     pub fn Gecko_LocalName(element: RawGeckoElementBorrowed) -> *mut nsIAtom;
 }