diff --git a/dom/animation/AnimationComparator.h b/dom/animation/AnimationComparator.h
index ff665e82aa..730d62f484 100644
--- a/dom/animation/AnimationComparator.h
+++ b/dom/animation/AnimationComparator.h
@@ -7,6 +7,8 @@
 #ifndef mozilla_AnimationComparator_h
 #define mozilla_AnimationComparator_h
 
+#include "mozilla/dom/Animation.h"
+
 namespace mozilla {
 
 // Although this file is called AnimationComparator, we don't actually
diff --git a/dom/animation/AnimationEffectReadOnly.cpp b/dom/animation/AnimationEffectReadOnly.cpp
index 63d633c2f1..7eb0880c72 100644
--- a/dom/animation/AnimationEffectReadOnly.cpp
+++ b/dom/animation/AnimationEffectReadOnly.cpp
@@ -6,6 +6,7 @@
 
 #include "mozilla/dom/AnimationEffectReadOnly.h"
 #include "mozilla/dom/AnimationEffectReadOnlyBinding.h"
+#include "mozilla/dom/Animation.h"
 #include "mozilla/AnimationUtils.h"
 #include "mozilla/FloatingPoint.h"
 
diff --git a/dom/animation/AnimationPerformanceWarning.h b/dom/animation/AnimationPerformanceWarning.h
index 025857e0c0..a1ac35cba0 100644
--- a/dom/animation/AnimationPerformanceWarning.h
+++ b/dom/animation/AnimationPerformanceWarning.h
@@ -9,6 +9,9 @@
 
 #include <initializer_list>
 
+#include "mozilla/Maybe.h"
+#include "nsTArray.h"
+
 class nsXPIDLString;
 
 namespace mozilla {
diff --git a/dom/animation/CSSPseudoElement.cpp b/dom/animation/CSSPseudoElement.cpp
index a4dede0b3b..0283eb59e6 100644
--- a/dom/animation/CSSPseudoElement.cpp
+++ b/dom/animation/CSSPseudoElement.cpp
@@ -7,6 +7,7 @@
 #include "mozilla/dom/CSSPseudoElement.h"
 #include "mozilla/dom/CSSPseudoElementBinding.h"
 #include "mozilla/dom/Element.h"
+#include "mozilla/dom/KeyFrameEffectBinding.h" // for ElementOrCSSPseudoElement class
 #include "mozilla/AnimationComparator.h"
 
 namespace mozilla {
diff --git a/dom/animation/KeyframeEffect.cpp b/dom/animation/KeyframeEffect.cpp
index decbf63050..32f6bd1a10 100644
--- a/dom/animation/KeyframeEffect.cpp
+++ b/dom/animation/KeyframeEffect.cpp
@@ -11,6 +11,7 @@
 #include "mozilla/dom/AnimationEffectTiming.h"
 #include "mozilla/dom/KeyframeEffectBinding.h"
 #include "mozilla/KeyframeUtils.h"
+#include "nsContentUtils.h"
 #include "nsDOMMutationObserver.h" // For nsAutoAnimationMutationBatch
 #include "nsIScriptError.h"
 
diff --git a/dom/animation/KeyframeEffectReadOnly.cpp b/dom/animation/KeyframeEffectReadOnly.cpp
index 164ee02925..5868790bb2 100644
--- a/dom/animation/KeyframeEffectReadOnly.cpp
+++ b/dom/animation/KeyframeEffectReadOnly.cpp
@@ -6,6 +6,7 @@
 
 #include "mozilla/dom/KeyframeEffectReadOnly.h"
 
+#include "mozilla/dom/Animation.h"
 #include "mozilla/dom/KeyframeAnimationOptionsBinding.h"
   // For UnrestrictedDoubleOrKeyframeAnimationOptions;
 #include "mozilla/dom/CSSPseudoElement.h"
@@ -25,6 +26,7 @@
 #include "nsCSSPseudoElements.h" // For CSSPseudoElementType
 #include "nsIPresShell.h"
 #include "nsIScriptError.h"
+#include "nsRefreshDriver.h"
 
 namespace mozilla {
 
diff --git a/dom/animation/moz.build b/dom/animation/moz.build
index bd8c937072..356980f002 100644
--- a/dom/animation/moz.build
+++ b/dom/animation/moz.build
@@ -37,6 +37,11 @@ EXPORTS.mozilla += [
 ]
 
 UNIFIED_SOURCES += [
+    'KeyframeEffect.cpp',
+    'KeyframeEffectReadOnly.cpp',
+]
+
+SOURCES += [
     'Animation.cpp',
     'AnimationEffectReadOnly.cpp',
     'AnimationEffectTiming.cpp',
@@ -50,9 +55,7 @@ UNIFIED_SOURCES += [
     'DocumentTimeline.cpp',
     'EffectCompositor.cpp',
     'EffectSet.cpp',
-    'KeyframeEffect.cpp',
     'KeyframeEffectParams.cpp',
-    'KeyframeEffectReadOnly.cpp',
     'KeyframeUtils.cpp',
     'PendingAnimationTracker.cpp',
     'TimingParams.cpp',