diff --git a/lib/optimize/ConcatenatedModule.js b/lib/optimize/ConcatenatedModule.js
index 61091c02b49..8031b3d61f9 100644
--- a/lib/optimize/ConcatenatedModule.js
+++ b/lib/optimize/ConcatenatedModule.js
@@ -156,6 +156,7 @@ class ConcatenatedModule extends Module {
 		this.dependenciesErrors = [];
 		this.warnings = [];
 		this.errors = [];
+		this.assets = {};
 		for(const m of modules) {
 			// populate dependencies
 			m.dependencies.filter(dep => !modulesSet.has(dep.module))
@@ -168,6 +169,8 @@ class ConcatenatedModule extends Module {
 			m.warnings.forEach(warning => this.warnings.push(warning));
 			// populate errors
 			m.errors.forEach(error => this.errors.push(error));
+
+			Object.assign(this.assets, m.assets);
 		}
 	}