diff --git a/src/plugin.js b/src/plugin.js
index cf6743f..5dfb1cc 100644
--- a/src/plugin.js
+++ b/src/plugin.js
@@ -87,7 +87,7 @@ class AutoDLLPlugin {
           compiler.hooks.autodllStatsRetrieved.call(stats, source);
 
           if (source === 'memory') return;
-          memory.sync(settings.hash, stats);
+          return memory.sync(settings.hash, stats);
         })
         .then(() => {
           attachDllReferencePlugin(compiler);