diff --git a/layout/style/ComputedStyle.h b/layout/style/ComputedStyle.h
index 737f2855df3d..32cefa75fdb9 100644
--- a/layout/style/ComputedStyle.h
+++ b/layout/style/ComputedStyle.h
@@ -15,6 +15,7 @@
 #include "mozilla/Maybe.h"
 #include "mozilla/PseudoStyleType.h"
 #include "mozilla/ServoComputedData.h"
+#include "mozilla/ServoComputedDataInlines.h"
 #include "mozilla/ServoStyleConsts.h"
 #include "mozilla/ServoTypes.h"
 #include "mozilla/ServoUtils.h"
diff --git a/layout/style/DeclarationBlock.cpp b/layout/style/DeclarationBlock.cpp
index 972fbebf1379..bb4d562fe22c 100644
--- a/layout/style/DeclarationBlock.cpp
+++ b/layout/style/DeclarationBlock.cpp
@@ -10,6 +10,7 @@
 #include "mozilla/ServoBindings.h"
 
 #include "nsCSSProps.h"
+#include "nsIMemoryReporter.h"
 
 namespace mozilla {
 
diff --git a/layout/style/FontFaceSet.cpp b/layout/style/FontFaceSet.cpp
index 0ff090097698..ca0024b6a99a 100644
--- a/layout/style/FontFaceSet.cpp
+++ b/layout/style/FontFaceSet.cpp
@@ -11,6 +11,7 @@
 #include "gfxFontSrcURI.h"
 #include "mozilla/css/Loader.h"
 #include "mozilla/dom/CSSFontFaceRule.h"
+#include "mozilla/dom/DocumentInlines.h"
 #include "mozilla/dom/Event.h"
 #include "mozilla/dom/FontFaceSetBinding.h"
 #include "mozilla/dom/FontFaceSetIterator.h"
diff --git a/layout/style/GeckoBindings.h b/layout/style/GeckoBindings.h
index 32bfb8b73616..9851ddf421cb 100644
--- a/layout/style/GeckoBindings.h
+++ b/layout/style/GeckoBindings.h
@@ -24,6 +24,7 @@ class nsAtom;
 class nsIURI;
 class nsSimpleContentList;
 struct nsFont;
+class ServoComputedData;
 
 namespace mozilla {
 class ComputedStyle;
diff --git a/layout/style/GroupRule.cpp b/layout/style/GroupRule.cpp
index 3b0b39995745..731149abb932 100644
--- a/layout/style/GroupRule.cpp
+++ b/layout/style/GroupRule.cpp
@@ -13,6 +13,8 @@
 
 #include "mozilla/dom/CSSRuleList.h"
 
+#include "nsPrintfCString.h"
+
 using namespace mozilla::dom;
 
 namespace mozilla {
diff --git a/layout/style/nsAnimationManager.cpp b/layout/style/nsAnimationManager.cpp
index 15f88c8a4f2d..eb18ea7115da 100644
--- a/layout/style/nsAnimationManager.cpp
+++ b/layout/style/nsAnimationManager.cpp
@@ -5,6 +5,7 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 #include "nsAnimationManager.h"
+#include "nsINode.h"
 #include "nsTransitionManager.h"
 #include "mozilla/dom/CSSAnimationBinding.h"
 
@@ -31,13 +32,26 @@
 #include <algorithm>  // std::stable_sort
 #include <math.h>
 
+namespace mozilla {
+namespace dom {
+struct ComputedEffectTiming;
+struct EffectTiming;
+struct OptionalEffectTiming;
+}  // namespace dom
+}  // namespace mozilla
+
 using namespace mozilla;
 using namespace mozilla::css;
 using mozilla::dom::Animation;
 using mozilla::dom::AnimationEffect;
 using mozilla::dom::AnimationPlayState;
+using mozilla::dom::ComputedEffectTiming;
 using mozilla::dom::CSSAnimation;
+using mozilla::dom::EffectTiming;
+using mozilla::dom::Element;
 using mozilla::dom::KeyframeEffect;
+using mozilla::dom::MutationObservers;
+using mozilla::dom::OptionalEffectTiming;
 
 typedef mozilla::ComputedTiming::AnimationPhase AnimationPhase;
 
diff --git a/layout/style/nsFontFaceUtils.cpp b/layout/style/nsFontFaceUtils.cpp
index 3b75bca0df75..3a760d4cafe9 100644
--- a/layout/style/nsFontFaceUtils.cpp
+++ b/layout/style/nsFontFaceUtils.cpp
@@ -167,8 +167,8 @@ void nsFontFaceUtils::MarkDirtyForFontChange(nsIFrame* aSubtreeRoot,
           MOZ_ASSERT(f->GetContent() && f->GetContent()->IsElement(),
                      "How could we target a non-element with selectors?");
           f->PresContext()->RestyleManager()->PostRestyleEvent(
-              Element::FromNode(f->GetContent()), RestyleHint::RECASCADE_SELF,
-              nsChangeHint(0));
+              dom::Element::FromNode(f->GetContent()),
+              RestyleHint::RECASCADE_SELF, nsChangeHint(0));
         }
       }
 
diff --git a/layout/style/nsStyleUtil.cpp b/layout/style/nsStyleUtil.cpp
index 1a08570ad7f3..a9d9f7af1bc8 100644
--- a/layout/style/nsStyleUtil.cpp
+++ b/layout/style/nsStyleUtil.cpp
@@ -276,7 +276,7 @@ bool nsStyleUtil::ObjectPropsMightCauseOverflow(
 
 /* static */
 bool nsStyleUtil::CSPAllowsInlineStyle(
-    Element* aElement, dom::Document* aDocument,
+    dom::Element* aElement, dom::Document* aDocument,
     nsIPrincipal* aTriggeringPrincipal, uint32_t aLineNumber,
     uint32_t aColumnNumber, const nsAString& aStyleText, nsresult* aRv) {
   nsresult rv;
diff --git a/layout/style/nsTransitionManager.cpp b/layout/style/nsTransitionManager.cpp
index b699c6607deb..c10fbe231414 100644
--- a/layout/style/nsTransitionManager.cpp
+++ b/layout/style/nsTransitionManager.cpp
@@ -7,6 +7,8 @@
 /* Code to start and animate CSS transitions. */
 
 #include "nsTransitionManager.h"
+#include "mozilla/dom/Document.h"
+#include "mozilla/dom/KeyframeEffectBinding.h"
 #include "nsAnimationManager.h"
 #include "mozilla/dom/CSSTransitionBinding.h"
 
@@ -40,6 +42,8 @@ using mozilla::TimeStamp;
 using mozilla::dom::Animation;
 using mozilla::dom::AnimationPlayState;
 using mozilla::dom::CSSTransition;
+using mozilla::dom::DocumentTimeline;
+using mozilla::dom::KeyframeEffect;
 using mozilla::dom::Nullable;
 
 using namespace mozilla;