diff --git a/dom/base/nsAttrValue.cpp b/dom/base/nsAttrValue.cpp
index 09d72d7a774f..7ac32a143d9a 100644
--- a/dom/base/nsAttrValue.cpp
+++ b/dom/base/nsAttrValue.cpp
@@ -17,7 +17,7 @@
 #include "nsIAtom.h"
 #include "nsUnicharUtils.h"
 #include "mozilla/MemoryReporting.h"
-#include "mozilla/ServoBindings.h"
+#include "mozilla/ServoBindingHelpers.h"
 #include "mozilla/css/Declaration.h"
 #include "nsContentUtils.h"
 #include "nsReadableUtils.h"
@@ -463,12 +463,12 @@ nsAttrValue::SetTo(css::Declaration* aValue, const nsAString* aSerialized)
 }
 
 void
-nsAttrValue::SetTo(ServoDeclarationBlock* aValue,
+nsAttrValue::SetTo(already_AddRefed<ServoDeclarationBlock> aValue,
                    const nsAString* aSerialized)
 {
   MiscContainer* cont = EnsureEmptyMiscContainer();
   MOZ_ASSERT(cont->mValue.mRefCount == 0);
-  cont->mValue.mServoCSSDeclaration = aValue;
+  cont->mValue.mServoCSSDeclaration = aValue.take();
   cont->mType = eServoCSSDeclaration;
   NS_ADDREF(cont);
   SetMiscAtomOrString(aSerialized);
@@ -1745,12 +1745,11 @@ nsAttrValue::ParseStyleAttribute(const nsAString& aString,
 
   if (ownerDoc->GetStyleBackendType() == StyleBackendType::Servo) {
     NS_ConvertUTF16toUTF8 value(aString);
-    ServoDeclarationBlock* decl = Servo_ParseStyleAttribute(
+    RefPtr<ServoDeclarationBlock> decl = Servo_ParseStyleAttribute(
         reinterpret_cast<const uint8_t*>(value.get()),
-        value.Length(),
-        sheet);
+        value.Length(), sheet).Consume();
     MOZ_ASSERT(decl);
-    SetTo(decl, &aString);
+    SetTo(decl.forget(), &aString);
   } else {
     css::Loader* cssLoader = ownerDoc->CSSLoader();
     nsCSSParser cssParser(cssLoader);
@@ -1862,7 +1861,7 @@ nsAttrValue::ClearMiscContainer()
           if (cont->mType == eGeckoCSSDeclaration) {
             NS_RELEASE(cont->mValue.mGeckoCSSDeclaration);
           } else {
-            Servo_DropDeclarationBlock(cont->mValue.mServoCSSDeclaration);
+            Servo_DeclarationBlock_Release(cont->mValue.mServoCSSDeclaration);
           }
           break;
         }
diff --git a/dom/base/nsAttrValue.h b/dom/base/nsAttrValue.h
index 6deaff3f3264..2587fc02c8f6 100644
--- a/dom/base/nsAttrValue.h
+++ b/dom/base/nsAttrValue.h
@@ -148,7 +148,7 @@ public:
   void SetTo(int32_t aInt, const nsAString* aSerialized);
   void SetTo(double aValue, const nsAString* aSerialized);
   void SetTo(mozilla::css::Declaration* aValue, const nsAString* aSerialized);
-  void SetTo(ServoDeclarationBlock* aDeclarationBlock,
+  void SetTo(already_AddRefed<ServoDeclarationBlock> aDeclarationBlock,
              const nsAString* aSerialized);
   void SetTo(mozilla::css::URLValue* aValue, const nsAString* aSerialized);
   void SetTo(const nsIntMargin& aValue);
diff --git a/layout/style/ServoBindingHelpers.h b/layout/style/ServoBindingHelpers.h
index 06e2b9f0e305..e6c638dfea01 100644
--- a/layout/style/ServoBindingHelpers.h
+++ b/layout/style/ServoBindingHelpers.h
@@ -45,6 +45,19 @@ public:
   }
 };
 
+template<>
+struct RefPtrTraits<ServoDeclarationBlock>
+{
+  static void AddRef(ServoDeclarationBlock* aPtr)
+  {
+    Servo_DeclarationBlock_AddRef(aPtr);
+  }
+  static void Release(ServoDeclarationBlock* aPtr)
+  {
+    Servo_DeclarationBlock_Release(aPtr);
+  }
+};
+
 } // namespace mozilla
 
 #endif // mozilla_ServoBindingHelpers_h
diff --git a/layout/style/ServoBindingList.h b/layout/style/ServoBindingList.h
index 71c8d60ddc18..3d4833bde958 100644
--- a/layout/style/ServoBindingList.h
+++ b/layout/style/ServoBindingList.h
@@ -49,17 +49,19 @@ SERVO_BINDING_FUNC(Servo_InitStyleSet, RawServoStyleSet*)
 SERVO_BINDING_FUNC(Servo_DropStyleSet, void, RawServoStyleSet* set)
 
 // Style attribute
-SERVO_BINDING_FUNC(Servo_ParseStyleAttribute, ServoDeclarationBlock*,
+SERVO_BINDING_FUNC(Servo_ParseStyleAttribute, ServoDeclarationBlockStrong,
                    const uint8_t* bytes, uint32_t length,
                    nsHTMLCSSStyleSheet* cache)
-SERVO_BINDING_FUNC(Servo_DropDeclarationBlock, void,
-                   ServoDeclarationBlock* declarations)
+SERVO_BINDING_FUNC(Servo_DeclarationBlock_AddRef, void,
+                   ServoDeclarationBlockBorrowed declarations)
+SERVO_BINDING_FUNC(Servo_DeclarationBlock_Release, void,
+                   ServoDeclarationBlockBorrowed declarations)
 SERVO_BINDING_FUNC(Servo_GetDeclarationBlockCache, nsHTMLCSSStyleSheet*,
-                   ServoDeclarationBlock* declarations)
+                   ServoDeclarationBlockBorrowed declarations)
 SERVO_BINDING_FUNC(Servo_SetDeclarationBlockImmutable, void,
-                   ServoDeclarationBlock* declarations)
+                   ServoDeclarationBlockBorrowed declarations)
 SERVO_BINDING_FUNC(Servo_ClearDeclarationBlockCachePointer, void,
-                   ServoDeclarationBlock* declarations)
+                   ServoDeclarationBlockBorrowed declarations)
 
 // CSS supports()
 SERVO_BINDING_FUNC(Servo_CSSSupports, bool,
diff --git a/layout/style/ServoBindings.cpp b/layout/style/ServoBindings.cpp
index 0d2957d4619f..fea0d50e1cf1 100644
--- a/layout/style/ServoBindings.cpp
+++ b/layout/style/ServoBindings.cpp
@@ -40,6 +40,7 @@ using namespace mozilla;
 
 IMPL_STRONG_REF_TYPE_FOR(ServoComputedValues)
 IMPL_STRONG_REF_TYPE_FOR(RawServoStyleSheet)
+IMPL_STRONG_REF_TYPE_FOR(ServoDeclarationBlock)
 
 #undef IMPL_STRONG_REF_TYPE_FOR
 
diff --git a/layout/style/ServoBindings.h b/layout/style/ServoBindings.h
index d1f403be425b..c3ed384f8443 100644
--- a/layout/style/ServoBindings.h
+++ b/layout/style/ServoBindings.h
@@ -65,6 +65,7 @@ struct ServoDeclarationBlock;
 
 DECL_REF_TYPE_FOR(ServoComputedValues)
 DECL_REF_TYPE_FOR(RawServoStyleSheet)
+DECL_REF_TYPE_FOR(ServoDeclarationBlock)
 
 #undef DECL_REF_TYPE_FOR
 
@@ -145,7 +146,7 @@ SERVO_DECLARE_ELEMENT_ATTR_MATCHING_FUNCTIONS(Gecko_Snapshot,
 #undef SERVO_DECLARE_ELEMENT_ATTR_MATCHING_FUNCTIONS
 
 // Style attributes.
-ServoDeclarationBlock* Gecko_GetServoDeclarationBlock(RawGeckoElement* element);
+ServoDeclarationBlockBorrowed Gecko_GetServoDeclarationBlock(RawGeckoElement* element);
 
 // Node data.
 ServoNodeData* Gecko_GetNodeData(RawGeckoNode* node);