diff --git a/src/apps.js b/src/apps.js
index b82404a8b..cf64494f5 100644
--- a/src/apps.js
+++ b/src/apps.js
@@ -758,6 +758,8 @@ function stop(appId, callback) {
 }
 
 function checkManifestConstraints(manifest) {
+    assert(manifest && typeof manifest === 'object');
+
     if (!manifest.dockerImage) return new AppsError(AppsError.BAD_FIELD, 'Missing dockerImage'); // dockerImage is optional in manifest
 
     if (semver.valid(manifest.maxBoxVersion) && semver.gt(config.version(), manifest.maxBoxVersion)) {