diff --git a/spine-unity/Assets/Spine/Editor/spine-unity/Editor/Components/ISkeletonRendererInspector.cs b/spine-unity/Assets/Spine/Editor/spine-unity/Editor/Components/ISkeletonRendererInspector.cs
index 28a57a9c0..f2d826f43 100644
--- a/spine-unity/Assets/Spine/Editor/spine-unity/Editor/Components/ISkeletonRendererInspector.cs
+++ b/spine-unity/Assets/Spine/Editor/spine-unity/Editor/Components/ISkeletonRendererInspector.cs
@@ -37,10 +37,6 @@
 #define PER_MATERIAL_PROPERTY_BLOCKS
 #endif
 
-#if UNITY_2017_1_OR_NEWER
-#define BUILT_IN_SPRITE_MASK_COMPONENT
-#endif
-
 using UnityEditor;
 using UnityEngine;
 
diff --git a/spine-unity/Assets/Spine/Runtime/spine-unity/Components/Base/SkeletonAnimationBase.cs b/spine-unity/Assets/Spine/Runtime/spine-unity/Components/Base/SkeletonAnimationBase.cs
index 606769702..15aacf63b 100644
--- a/spine-unity/Assets/Spine/Runtime/spine-unity/Components/Base/SkeletonAnimationBase.cs
+++ b/spine-unity/Assets/Spine/Runtime/spine-unity/Components/Base/SkeletonAnimationBase.cs
@@ -35,10 +35,6 @@
 #define PER_MATERIAL_PROPERTY_BLOCKS
 #endif
 
-#if UNITY_2017_1_OR_NEWER
-#define BUILT_IN_SPRITE_MASK_COMPONENT
-#endif
-
 #if UNITY_2019_3_OR_NEWER
 #define CONFIGURABLE_ENTER_PLAY_MODE
 #endif
diff --git a/spine-unity/Assets/Spine/Runtime/spine-unity/Components/SkeletonGraphic.Common.cs b/spine-unity/Assets/Spine/Runtime/spine-unity/Components/SkeletonGraphic.Common.cs
index c36507804..42e1a1a07 100644
--- a/spine-unity/Assets/Spine/Runtime/spine-unity/Components/SkeletonGraphic.Common.cs
+++ b/spine-unity/Assets/Spine/Runtime/spine-unity/Components/SkeletonGraphic.Common.cs
@@ -35,10 +35,6 @@
 #define PER_MATERIAL_PROPERTY_BLOCKS
 #endif
 
-#if UNITY_2017_1_OR_NEWER
-#define BUILT_IN_SPRITE_MASK_COMPONENT
-#endif
-
 #if UNITY_2019_3_OR_NEWER
 #define CONFIGURABLE_ENTER_PLAY_MODE
 #endif
diff --git a/spine-unity/Assets/Spine/Runtime/spine-unity/Components/SkeletonRenderer.Common.cs b/spine-unity/Assets/Spine/Runtime/spine-unity/Components/SkeletonRenderer.Common.cs
index 420e45f59..42f7fe1de 100644
--- a/spine-unity/Assets/Spine/Runtime/spine-unity/Components/SkeletonRenderer.Common.cs
+++ b/spine-unity/Assets/Spine/Runtime/spine-unity/Components/SkeletonRenderer.Common.cs
@@ -35,10 +35,6 @@
 #define PER_MATERIAL_PROPERTY_BLOCKS
 #endif
 
-#if UNITY_2017_1_OR_NEWER
-#define BUILT_IN_SPRITE_MASK_COMPONENT
-#endif
-
 #if UNITY_2019_3_OR_NEWER
 #define CONFIGURABLE_ENTER_PLAY_MODE
 #endif
diff --git a/spine-unity/Assets/Spine/Runtime/spine-unity/Components/SkeletonRenderer.cs b/spine-unity/Assets/Spine/Runtime/spine-unity/Components/SkeletonRenderer.cs
index fc79cc1f6..e6c07ab65 100644
--- a/spine-unity/Assets/Spine/Runtime/spine-unity/Components/SkeletonRenderer.cs
+++ b/spine-unity/Assets/Spine/Runtime/spine-unity/Components/SkeletonRenderer.cs
@@ -121,7 +121,7 @@ namespace Spine.Unity {
 
 #if BUILT_IN_SPRITE_MASK_COMPONENT
 		/// <seealso cref="MaskInteraction"/>
-		protected SpriteMaskInteraction maskInteraction = SpriteMaskInteraction.None;
+		[SerializeField] protected SpriteMaskInteraction maskInteraction = SpriteMaskInteraction.None;
 
 		/// <summary>Cached reference to the already setup material override set at the respective
 		/// SkeletonDataAsset.atlasAssets array entry.</summary>
diff --git a/spine-unity/Assets/Spine/package.json b/spine-unity/Assets/Spine/package.json
index b990bda95..a5e288c03 100644
--- a/spine-unity/Assets/Spine/package.json
+++ b/spine-unity/Assets/Spine/package.json
@@ -2,7 +2,7 @@
 	"name": "com.esotericsoftware.spine.spine-unity",
 	"displayName": "spine-unity Runtime",
 	"description": "This plugin provides the spine-unity runtime core and examples. Spine Examples can be installed via the Samples tab.",
-	"version": "4.3.35",
+	"version": "4.3.36",
 	"unity": "2018.3",
 	"author": {
 		"name": "Esoteric Software",