--- a/layout/style/ServoBindings.h
+++ b/layout/style/ServoBindings.h
@@ -550,15 +550,21 @@ void Gecko_UnregisterProfilerThread();
 
 bool Gecko_DocumentRule_UseForPresentation(RawGeckoPresContextBorrowed,
                                            const nsACString* aPattern,
                                            mozilla::css::URLMatchingFunction aURLMatchingFunction);
 
 // Allocator hinting.
 void Gecko_SetJemallocThreadLocalArena(bool enabled);
 
+// Pseudo-element flags.
+#define CSS_PSEUDO_ELEMENT(name_, value_, flags_) \
+  const uint32_t SERVO_CSS_PSEUDO_ELEMENT_FLAGS_##name_ = flags_;
+#include "nsCSSPseudoElementList.h"
+#undef CSS_PSEUDO_ELEMENT
+
 #define SERVO_BINDING_FUNC(name_, return_, ...) return_ name_(__VA_ARGS__);
 #include "mozilla/ServoBindingList.h"
 #undef SERVO_BINDING_FUNC
 
 } // extern "C"
 
 #endif // mozilla_ServoBindings_h