--- a/servo/ports/geckolib/glue.rs
+++ b/servo/ports/geckolib/glue.rs
@@ -503,16 +503,17 @@ pub extern "C" fn Servo_Element_ClearDat
 
 #[no_mangle]
 pub extern "C" fn Servo_StyleSheet_Empty(mode: SheetParsingMode) -> RawServoStyleSheetStrong {
     let global_style_data = &*GLOBAL_STYLE_DATA;
     let origin = match mode {
         SheetParsingMode::eAuthorSheetFeatures => Origin::Author,
         SheetParsingMode::eUserSheetFeatures => Origin::User,
         SheetParsingMode::eAgentSheetFeatures => Origin::UserAgent,
+        SheetParsingMode::eSafeAgentSheetFeatures => Origin::UserAgent,
     };
     let shared_lock = global_style_data.shared_lock.clone();
     Arc::new(Stylesheet::from_str(
         "", unsafe { dummy_url_data() }.clone(), origin,
         Arc::new(shared_lock.wrap(MediaList::empty())),
         shared_lock, None, &RustLogReporter, QuirksMode::NoQuirks, 0u64)
     ).into_strong()
 }
@@ -527,16 +528,17 @@ pub extern "C" fn Servo_StyleSheet_FromU
                                                  -> RawServoStyleSheetStrong {
     let global_style_data = &*GLOBAL_STYLE_DATA;
     let input = unsafe { data.as_ref().unwrap().as_str_unchecked() };
 
     let origin = match mode {
         SheetParsingMode::eAuthorSheetFeatures => Origin::Author,
         SheetParsingMode::eUserSheetFeatures => Origin::User,
         SheetParsingMode::eAgentSheetFeatures => Origin::UserAgent,
+        SheetParsingMode::eSafeAgentSheetFeatures => Origin::UserAgent,
     };
 
     let url_data = unsafe { RefPtr::from_ptr_ref(&extra_data) };
     let loader = if loader.is_null() {
         None
     } else {
         Some(StylesheetLoader::new(loader, stylesheet))
     };