diff --git a/spine-unity/Assets/Spine/Editor/spine-unity/Editor/Utility/SpineBuildProcessor.cs b/spine-unity/Assets/Spine/Editor/spine-unity/Editor/Utility/SpineBuildProcessor.cs
new file mode 100644
index 000000000..47972c356
--- /dev/null
+++ b/spine-unity/Assets/Spine/Editor/spine-unity/Editor/Utility/SpineBuildProcessor.cs
@@ -0,0 +1,132 @@
+/******************************************************************************
+ * Spine Runtimes License Agreement
+ * Last updated January 1, 2020. Replaces all prior versions.
+ *
+ * Copyright (c) 2013-2020, Esoteric Software LLC
+ *
+ * Integration of the Spine Runtimes into software or otherwise creating
+ * derivative works of the Spine Runtimes is permitted under the terms and
+ * conditions of Section 2 of the Spine Editor License Agreement:
+ * http://esotericsoftware.com/spine-editor-license
+ *
+ * Otherwise, it is permitted to integrate the Spine Runtimes into software
+ * or otherwise create derivative works of the Spine Runtimes (collectively,
+ * "Products"), provided that each user of the Products must obtain their own
+ * Spine Editor license and redistribution of the Products in any form must
+ * include this license and copyright notice.
+ *
+ * THE SPINE RUNTIMES ARE PROVIDED BY ESOTERIC SOFTWARE LLC "AS IS" AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL ESOTERIC SOFTWARE LLC BE LIABLE FOR ANY
+ * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES,
+ * BUSINESS INTERRUPTION, OR LOSS OF USE, DATA, OR PROFITS) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THE SPINE RUNTIMES, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *****************************************************************************/
+
+
+#if UNITY_2018_1_OR_NEWER
+#define HAS_BUILD_PROCESS_WITH_REPORT
+#endif
+
+#if UNITY_2020_2_OR_NEWER
+#define HAS_ON_POSTPROCESS_PREFAB
+#endif
+
+using UnityEngine;
+using UnityEditor;
+using System.Collections.Generic;
+using UnityEditor.Build;
+#if HAS_BUILD_PROCESS_WITH_REPORT
+using UnityEditor.Build.Reporting;
+#endif
+
+namespace Spine.Unity.Editor {
+	public class SpineBuildProcessor
+	{
+		internal static bool isBuilding = false;
+
+#if HAS_ON_POSTPROCESS_PREFAB
+		static List<string> prefabsToRestore = new List<string>();
+#endif
+
+		internal static void PreprocessBuild()
+		{
+			isBuilding = true;
+#if HAS_ON_POSTPROCESS_PREFAB
+			var assets = AssetDatabase.FindAssets("t:Prefab");
+			foreach(var asset in assets) {
+				string assetPath = AssetDatabase.GUIDToAssetPath(asset);
+				GameObject g = AssetDatabase.LoadAssetAtPath<GameObject>(assetPath);
+				if (SpineEditorUtilities.CleanupSpinePrefabMesh(g)) {
+					prefabsToRestore.Add(assetPath);
+				}
+			}
+			AssetDatabase.SaveAssets();
+#endif
+		}
+
+		internal static void PostprocessBuild()
+		{
+			isBuilding = false;
+#if HAS_ON_POSTPROCESS_PREFAB
+			foreach (string assetPath in prefabsToRestore) {
+				GameObject g = AssetDatabase.LoadAssetAtPath<GameObject>(assetPath);
+				SpineEditorUtilities.SetupSpinePrefabMesh(g, null);
+			}
+			AssetDatabase.SaveAssets();
+#endif
+		}
+	}
+
+	public class SpineBuildPreprocessor :
+#if HAS_BUILD_PROCESS_WITH_REPORT
+		IPreprocessBuildWithReport
+#else
+		IPreprocessBuild
+#endif
+	{
+		public int callbackOrder {
+			get { return -2000; }
+		}
+#if HAS_BUILD_PROCESS_WITH_REPORT
+		void IPreprocessBuildWithReport.OnPreprocessBuild(BuildReport report)
+		{
+			SpineBuildProcessor.PreprocessBuild();
+		}
+#else
+		void IPreprocessBuild.OnPreprocessBuild(BuildTarget target, string path)
+		{
+			SpineBuildProcessor.PreprocessBuild();
+		}
+#endif
+	}
+
+	public class SpineBuildPostprocessor :
+#if HAS_BUILD_PROCESS_WITH_REPORT
+		IPostprocessBuildWithReport
+#else
+		IPostprocessBuild
+#endif
+	{
+		public int callbackOrder {
+			get { return 2000; }
+		}
+
+
+#if HAS_BUILD_PROCESS_WITH_REPORT
+		void IPostprocessBuildWithReport.OnPostprocessBuild(BuildReport report)
+		{
+			SpineBuildProcessor.PostprocessBuild();
+		}
+#else
+		void IPostprocessBuild.OnPostprocessBuild(BuildTarget target, string path)
+		{
+			SpineBuildProcessor.PostprocessBuild();
+		}
+#endif
+	}
+}
diff --git a/spine-unity/Assets/Spine/Editor/spine-unity/Editor/Utility/SpineBuildProcessor.cs.meta b/spine-unity/Assets/Spine/Editor/spine-unity/Editor/Utility/SpineBuildProcessor.cs.meta
new file mode 100644
index 000000000..09f96e801
--- /dev/null
+++ b/spine-unity/Assets/Spine/Editor/spine-unity/Editor/Utility/SpineBuildProcessor.cs.meta
@@ -0,0 +1,11 @@
+fileFormatVersion: 2
+guid: ca21cb19ac5068ee796e6cb09ff11e5d
+MonoImporter:
+  externalObjects: {}
+  serializedVersion: 2
+  defaultReferences: []
+  executionOrder: 0
+  icon: {instanceID: 0}
+  userData: 
+  assetBundleName: 
+  assetBundleVariant: 
diff --git a/spine-unity/Assets/Spine/Editor/spine-unity/Editor/Utility/SpineEditorUtilities.cs b/spine-unity/Assets/Spine/Editor/spine-unity/Editor/Utility/SpineEditorUtilities.cs
index b5cb25e5a..c469e0ed7 100644
--- a/spine-unity/Assets/Spine/Editor/spine-unity/Editor/Utility/SpineEditorUtilities.cs
+++ b/spine-unity/Assets/Spine/Editor/spine-unity/Editor/Utility/SpineEditorUtilities.cs
@@ -102,8 +102,18 @@ namespace Spine.Unity.Editor {
 #if HAS_ON_POSTPROCESS_PREFAB
 		// Post process prefabs for setting the MeshFilter to not cause constant Prefab override changes.
 		void OnPostprocessPrefab (GameObject g) {
+			if (SpineBuildProcessor.isBuilding)
+				return;
+
+			SetupSpinePrefabMesh(g, context);
+		}
+
+		public static bool SetupSpinePrefabMesh(GameObject g, UnityEditor.AssetImporters.AssetImportContext context)
+		{
+			bool wasModified = false;
 			var skeletonRenderers = g.GetComponentsInChildren<SkeletonRenderer>(true);
 			foreach (SkeletonRenderer renderer in skeletonRenderers) {
+				wasModified = true;
 				var meshFilter = renderer.GetComponent<MeshFilter>();
 				if (meshFilter == null)
 					meshFilter = renderer.gameObject.AddComponent<MeshFilter>();
@@ -114,9 +124,27 @@ namespace Spine.Unity.Editor {
 				var mesh = meshFilter.sharedMesh;
 				string meshName = string.Format("Skeleton Prefab Mesh \"{0}\"", renderer.name);
 				mesh.name = meshName;
-				mesh.hideFlags = HideFlags.DontSaveInEditor; // removed flag DontSaveInBuild, prevents a build error when the prefab is referenced
-				context.AddObjectToAsset(meshName, mesh);
+				if (context != null)
+					context.AddObjectToAsset(meshFilter.sharedMesh.name, meshFilter.sharedMesh);
 			}
+			return wasModified;
+		}
+
+		public static bool CleanupSpinePrefabMesh(GameObject g)
+		{
+			bool wasModified = false;
+			var skeletonRenderers = g.GetComponentsInChildren<SkeletonRenderer>(true);
+			foreach (SkeletonRenderer renderer in skeletonRenderers) {
+				var meshFilter = renderer.GetComponent<MeshFilter>();
+				if (meshFilter != null) {
+					if (meshFilter.sharedMesh) {
+						wasModified = true;
+						meshFilter.sharedMesh = null;
+						meshFilter.hideFlags = HideFlags.None;
+					}
+				}
+			}
+			return wasModified;
 		}
 #endif