diff --git a/components/style/gecko/non_ts_pseudo_class_list.rs b/components/style/gecko/non_ts_pseudo_class_list.rs
index 17ffd0e7046..c26c1cc98b6 100644
--- a/components/style/gecko/non_ts_pseudo_class_list.rs
+++ b/components/style/gecko/non_ts_pseudo_class_list.rs
@@ -64,6 +64,7 @@ macro_rules! apply_non_ts_list {
                 // TODO(emilio): Needs pref check for
                 // full-screen-api.unprefix.enabled!
                 ("fullscreen", Fullscreen, fullscreen, IN_FULLSCREEN_STATE, _),
+                ("-moz-full-screen", MozFullScreen, mozFullScreen, IN_FULLSCREEN_STATE, _),
                 // TODO(emilio): This is inconsistently named (the capital R).
                 ("-moz-focusring", MozFocusRing, mozFocusRing, IN_FOCUSRING_STATE, _),
                 ("-moz-broken", MozBroken, mozBroken, IN_BROKEN_STATE, _),
diff --git a/components/style/gecko/wrapper.rs b/components/style/gecko/wrapper.rs
index 1602c8a1d06..a6bce77ee71 100644
--- a/components/style/gecko/wrapper.rs
+++ b/components/style/gecko/wrapper.rs
@@ -1665,6 +1665,7 @@ impl<'le> ::selectors::Element for GeckoElement<'le> {
             NonTSPseudoClass::Disabled |
             NonTSPseudoClass::Checked |
             NonTSPseudoClass::Fullscreen |
+            NonTSPseudoClass::MozFullScreen |
             NonTSPseudoClass::Indeterminate |
             NonTSPseudoClass::PlaceholderShown |
             NonTSPseudoClass::Target |