diff --git a/Sources/kha/internal/AssetsBuilder.hx b/Sources/kha/internal/AssetsBuilder.hx
index 529e2b4d0..b5285cfec 100644
--- a/Sources/kha/internal/AssetsBuilder.hx
+++ b/Sources/kha/internal/AssetsBuilder.hx
@@ -6,13 +6,17 @@ import haxe.macro.Context;
 import haxe.macro.Expr;
 #if macro
 import sys.io.File;
+import sys.FileSystem;
 #end
 
 using StringTools;
 
 class AssetsBuilder {
 	#if macro
-	public static var files: Array<Dynamic>;
+	@:persistent static var cache: Map<String, {time: Float, fields: Array<Field>}> = [];
+	@:persistent static var files: Array<Dynamic>;
+	@:persistent static var filesTime: Float = 0.0;
+	static var debug = false;
 	#end
 
 	public static function findResources(): String {
@@ -51,18 +55,31 @@ class AssetsBuilder {
 	}
 
 	macro static public function build(type: String): Array<Field> {
-		var fields = Context.getBuildFields();
-		if (files == null) {
-			var content = Json.parse(File.getContent(findResources() + "files.json"));
+		final fields = Context.getBuildFields();
+		final resPath = findResources() + "files.json";
+		Context.registerModuleDependency(Context.getLocalModule(), resPath);
+
+		final time = FileSystem.stat(resPath).mtime.getTime();
+		if (cache[type] != null && cache[type].time == time) {
+			return cache[type].fields;
+		}
+
+		if (files == null || filesTime != time) {
+			final content = Json.parse(File.getContent(resPath));
 			files = content.files;
+			filesTime = time;
+			if (debug)
+				trace("reparse files.json (Assets)");
 		}
+		if (debug)
+			trace('invalidate Assets.$type');
 
-		var names = new Array<Expr>();
+		final names = new Array<Expr>();
 
 		for (file in files) {
-			var name = file.name;
+			final name = file.name;
 			final pos = Context.currentPos();
-			var filesize: Int = file.file_sizes[0];
+			final filesize: Int = file.file_sizes[0];
 
 			if (file.type == type) {
 				names.push(macro $v{name});
@@ -210,6 +227,10 @@ class AssetsBuilder {
 			kind: FVar(macro : Array<String>, macro $a{names}),
 			pos: Context.currentPos()
 		});
+		cache[type] = {
+			fields: fields,
+			time: time,
+		};
 
 		return fields;
 	}
diff --git a/Sources/kha/internal/ShadersBuilder.hx b/Sources/kha/internal/ShadersBuilder.hx
index d86a7096e..4bba00779 100644
--- a/Sources/kha/internal/ShadersBuilder.hx
+++ b/Sources/kha/internal/ShadersBuilder.hx
@@ -6,25 +6,32 @@ import haxe.macro.Expr.Field;
 import haxe.Serializer;
 #if macro
 import sys.io.File;
+import sys.FileSystem;
 #end
 
 using StringTools;
 
 class ShadersBuilder {
 	#if macro
-	public static var files: Array<Dynamic>;
+	@:persistent static var cache: {time: Float, fields: Array<Field>} = null;
+	static var debug = false;
 	#end
 
 	macro static public function build(): Array<Field> {
-		var fields = Context.getBuildFields();
-
-		var manifestPath = AssetsBuilder.findResources() + "files.json";
-		var content = Json.parse(File.getContent(manifestPath));
-
+		final fields = Context.getBuildFields();
+		final manifestPath = AssetsBuilder.findResources() + "files.json";
 		// rebuild Shaders module whenever manifest file is changed
 		Context.registerModuleDependency(Context.getLocalModule(), manifestPath);
 
-		files = content.files;
+		final time = FileSystem.stat(manifestPath).mtime.getTime();
+		if (cache != null && time == cache.time) {
+			return cache.fields;
+		}
+
+		final content = Json.parse(File.getContent(manifestPath));
+		final files: Array<Dynamic> = content.files;
+		if (debug)
+			trace("invalidate Shaders");
 
 		var init = macro {};
 
@@ -204,6 +211,10 @@ class ShadersBuilder {
 			}),
 			pos: Context.currentPos()
 		});
+		cache = {
+			fields: fields,
+			time: time,
+		};
 
 		return fields;
 	}