diff --git a/lib/optimize/ConcatenatedModule.js b/lib/optimize/ConcatenatedModule.js
index 5a09da769..e11aaefdb 100644
--- a/lib/optimize/ConcatenatedModule.js
+++ b/lib/optimize/ConcatenatedModule.js
@@ -110,7 +110,7 @@ class ConcatenatedModule extends Module {
 	}
 
 	libIdent(options) {
-		return this.modules.map(m => m.libIdent(options)).join(" ");
+		return this.rootModule.libIdent(options);
 	}
 
 	nameForCondition() {