diff --git a/platform/external-system-api/resources/i18n/ExternalSystemBundle.properties b/platform/external-system-api/resources/i18n/ExternalSystemBundle.properties
index 868aec0ba58f..2153e4b2471c 100644
--- a/platform/external-system-api/resources/i18n/ExternalSystemBundle.properties
+++ b/platform/external-system-api/resources/i18n/ExternalSystemBundle.properties
@@ -45,4 +45,5 @@ run.configuration.settings.label.project={0} project:
 run.configuration.settings.label.tasks=Tasks:
 run.configuration.settings.label.vmoptions=VM options:
 run.configuration.settings.caption.vmoptions=VM options:
-run.text.starting=Executing external tasks ''{0}''...
\ No newline at end of file
+run.text.starting=Executing external tasks ''{0}''...
+run.error.undefined.task=No task to execute is specified
\ No newline at end of file
diff --git a/platform/external-system-impl/src/com/intellij/openapi/externalSystem/service/execution/ExternalSystemRunConfiguration.java b/platform/external-system-impl/src/com/intellij/openapi/externalSystem/service/execution/ExternalSystemRunConfiguration.java
index ed5b60bd632b..b4e3c90d5872 100644
--- a/platform/external-system-impl/src/com/intellij/openapi/externalSystem/service/execution/ExternalSystemRunConfiguration.java
+++ b/platform/external-system-impl/src/com/intellij/openapi/externalSystem/service/execution/ExternalSystemRunConfiguration.java
@@ -109,6 +109,9 @@ public class ExternalSystemRunConfiguration extends RunConfigurationBase {
         for (String taskName : mySettings.getTaskNames()) {
           tasks.add(new ExternalTaskPojo(taskName, mySettings.getExternalProjectPath(), null));
         }
+        if (tasks.isEmpty()) {
+          throw new ExecutionException(ExternalSystemBundle.message("run.error.undefined.task"));
+        }
         final ExternalSystemExecuteTaskTask task = new ExternalSystemExecuteTaskTask(mySettings.getExternalSystemId(),
                                                                                      getProject(),
                                                                                      tasks,