diff --git a/layout/style/ServoBindings.cpp b/layout/style/ServoBindings.cpp
index 4afa9711c0b5..9c52dd8473af 100644
--- a/layout/style/ServoBindings.cpp
+++ b/layout/style/ServoBindings.cpp
@@ -1182,6 +1182,8 @@ CreateStyleImageRequest(nsStyleImageRequest::Mode aModeFlags,
   return req.forget();
 }
 
+NS_IMPL_THREADSAFE_FFI_REFCOUNTING(mozilla::css::ImageValue, ImageValue);
+
 void
 Gecko_SetUrlImageValue(nsStyleImage* aImage, ServoBundledURI aURI)
 {
diff --git a/layout/style/ServoBindings.h b/layout/style/ServoBindings.h
index 856978a66ef2..86018705c26e 100644
--- a/layout/style/ServoBindings.h
+++ b/layout/style/ServoBindings.h
@@ -40,6 +40,7 @@ namespace mozilla {
   struct StyleTransition;
   namespace css {
     struct URLValue;
+    struct ImageValue;
   };
   enum class UpdateAnimationsTasks : uint8_t;
   struct LangGroupFontPrefs;
@@ -272,6 +273,7 @@ void Gecko_CopyListStyleTypeFrom(nsStyleList* dst, const nsStyleList* src);
 // background-image style.
 void Gecko_SetNullImageValue(nsStyleImage* image);
 void Gecko_SetGradientImageValue(nsStyleImage* image, nsStyleGradient* gradient);
+NS_DECL_THREADSAFE_FFI_REFCOUNTING(mozilla::css::ImageValue, ImageValue);
 void Gecko_SetUrlImageValue(nsStyleImage* image,
                             ServoBundledURI uri);
 void Gecko_SetImageElement(nsStyleImage* image, nsIAtom* atom);