diff --git a/components/style/element_state.rs b/components/style/element_state.rs
index 2e3ccb3b31b..5dc3cc0c25d 100644
--- a/components/style/element_state.rs
+++ b/components/style/element_state.rs
@@ -144,6 +144,8 @@ bitflags! {
         const IN_MOZINERT_STATE = 1 << 54;
         /// State for the topmost dialog element in top layer
         const IN_TOPMOST_MODAL_DIALOG_STATE = 1 << 55;
+        /// Non-standard & undocumented.
+        const IN_HANDLER_NOPLUGINS = 1 << 56;
     }
 }
 
diff --git a/components/style/gecko/non_ts_pseudo_class_list.rs b/components/style/gecko/non_ts_pseudo_class_list.rs
index 0b34cd8d966..d1e49036d90 100644
--- a/components/style/gecko/non_ts_pseudo_class_list.rs
+++ b/components/style/gecko/non_ts_pseudo_class_list.rs
@@ -72,6 +72,8 @@ macro_rules! apply_non_ts_list {
                 ("-moz-handler-disabled", MozHandlerDisabled, IN_HANDLER_DISABLED_STATE, PSEUDO_CLASS_ENABLED_IN_UA_SHEETS_AND_CHROME),
                 ("-moz-handler-blocked", MozHandlerBlocked, IN_HANDLER_BLOCKED_STATE, PSEUDO_CLASS_ENABLED_IN_UA_SHEETS_AND_CHROME),
                 ("-moz-handler-crashed", MozHandlerCrashed, IN_HANDLER_CRASHED_STATE, PSEUDO_CLASS_ENABLED_IN_UA_SHEETS_AND_CHROME),
+                ("-moz-handler-noplugins", MozHandlerNoPlugins, IN_HANDLER_NOPLUGINS, PSEUDO_CLASS_ENABLED_IN_UA_SHEETS_AND_CHROME),
+
                 ("-moz-math-increment-script-level", MozMathIncrementScriptLevel, IN_INCREMENT_SCRIPT_LEVEL_STATE, _),
 
                 ("required", Required, IN_REQUIRED_STATE, _),
diff --git a/components/style/gecko/wrapper.rs b/components/style/gecko/wrapper.rs
index 932685ea3c1..847b822b28d 100644
--- a/components/style/gecko/wrapper.rs
+++ b/components/style/gecko/wrapper.rs
@@ -2046,6 +2046,7 @@ impl<'le> ::selectors::Element for GeckoElement<'le> {
             NonTSPseudoClass::MozHandlerClickToPlay |
             NonTSPseudoClass::MozHandlerVulnerableUpdatable |
             NonTSPseudoClass::MozHandlerVulnerableNoUpdate |
+            NonTSPseudoClass::MozHandlerNoPlugins |
             NonTSPseudoClass::MozMathIncrementScriptLevel |
             NonTSPseudoClass::InRange |
             NonTSPseudoClass::OutOfRange |