diff --git a/components/style/properties/gecko.mako.rs b/components/style/properties/gecko.mako.rs
index 3d972aeadfa..3822acb952a 100644
--- a/components/style/properties/gecko.mako.rs
+++ b/components/style/properties/gecko.mako.rs
@@ -4021,6 +4021,10 @@ clip-path
                 self.gecko.mContextPropsBits |= structs::NS_STYLE_CONTEXT_PROPERTY_FILL as u8;
             } else if servo.0 == atom!("stroke") {
                 self.gecko.mContextPropsBits |= structs::NS_STYLE_CONTEXT_PROPERTY_STROKE as u8;
+            } else if servo.0 == atom!("fill-opacity") {
+                self.gecko.mContextPropsBits |= structs::NS_STYLE_CONTEXT_PROPERTY_FILL_OPACITY as u8;
+            } else if servo.0 == atom!("stroke-opacity") {
+                self.gecko.mContextPropsBits |= structs::NS_STYLE_CONTEXT_PROPERTY_STROKE_OPACITY as u8;
             }
             unsafe { gecko.set_raw_from_addrefed::<structs::nsIAtom>(servo.0.into_addrefed()) }
         }