diff --git a/layout/style/ServoBindings.cpp b/layout/style/ServoBindings.cpp
index d350deff9831..1cd0a3246a49 100644
--- a/layout/style/ServoBindings.cpp
+++ b/layout/style/ServoBindings.cpp
@@ -577,7 +577,6 @@ void
 Gecko_UpdateAnimations(RawGeckoElementBorrowed aElement,
                        ServoComputedValuesBorrowedOrNull aOldComputedValues,
                        ServoComputedValuesBorrowedOrNull aComputedValues,
-                       ServoComputedValuesBorrowedOrNull aParentComputedValues,
                        UpdateAnimationsTasks aTasks)
 {
   MOZ_ASSERT(NS_IsMainThread());
diff --git a/layout/style/ServoBindings.h b/layout/style/ServoBindings.h
index 830eb1cdcfe7..02ae949134db 100644
--- a/layout/style/ServoBindings.h
+++ b/layout/style/ServoBindings.h
@@ -222,7 +222,6 @@ bool Gecko_StyleAnimationsEquals(RawGeckoStyleAnimationListBorrowed,
 void Gecko_UpdateAnimations(RawGeckoElementBorrowed aElementOrPseudo,
                             ServoComputedValuesBorrowedOrNull aOldComputedValues,
                             ServoComputedValuesBorrowedOrNull aComputedValues,
-                            ServoComputedValuesBorrowedOrNull aParentComputedValues,
                             mozilla::UpdateAnimationsTasks aTasks);
 bool Gecko_ElementHasAnimations(RawGeckoElementBorrowed aElementOrPseudo);
 bool Gecko_ElementHasCSSAnimations(RawGeckoElementBorrowed aElementOrPseudo);