diff --git a/lib/environment.js b/lib/environment.js
index 9b7722c0..5011ebb6 100644
--- a/lib/environment.js
+++ b/lib/environment.js
@@ -164,7 +164,7 @@ class Environment extends Base {
       rootCommand.emit('yeoman:environment', command.env);
 
       const generator = command.env.instantiate(GeneratorClass, this.args, this.opts());
-      command.env.queueGenerator(generator);
+      await command.env.queueGenerator(generator);
       return command.env.start().then(() => command.env);
     });
     return command;
@@ -922,29 +922,26 @@ class Environment extends Base {
         // Generator > 5
         this.once('run', () => generator.emit('run'));
         this.once('end', () => generator.emit('end'));
-        generator.queueTasks();
-      } else {
-        if (!generator.options.forwardErrorToEnvironment) {
-          generator.on('error', error => this.emit('error', error));
-        }
-        generator.promise = generator.run();
+        return generator.queueTasks();
+      }
+      if (!generator.options.forwardErrorToEnvironment) {
+        generator.on('error', error => this.emit('error', error));
       }
+      generator.promise = generator.run();
     };
 
     if (schedule) {
       this.runLoop.add(
         'environment:run',
-        (done, stop) => {
-          try {
-            runGenerator();
-            done();
-          } catch (error) {
-            stop(error);
-          }
+        async () => {
+          await runGenerator();
         }
       );
     } else {
-      runGenerator();
+      const maybePromise = runGenerator();
+      if (maybePromise && maybePromise.then) {
+        return maybePromise.then(() => generator);
+      }
     }
     return generator;
   }
@@ -1065,7 +1062,7 @@ class Environment extends Base {
   async runGenerator(generator) {
     try {
       generator = await generator;
-      generator = this.queueGenerator(generator);
+      generator = await this.queueGenerator(generator);
     } catch (error) {
       return Promise.reject(error);
     }