diff --git a/simulator-common/src/main/java/de/dentrassi/hono/demo/common/Registration.java b/simulator-common/src/main/java/de/dentrassi/hono/demo/common/Registration.java
index 74b2fe1..d52678a 100644
--- a/simulator-common/src/main/java/de/dentrassi/hono/demo/common/Registration.java
+++ b/simulator-common/src/main/java/de/dentrassi/hono/demo/common/Registration.java
@@ -53,6 +53,7 @@ public static Optional<Registration> fromEnv(final String tenantId) {
         }
 
         final Version version = Environment.get("DEVICE_REGISTRY_VERSION")
+                .filter(s -> !s.isBlank())
                 .map(String::toUpperCase)
                 .map(Version::valueOf)
                 .orElse(Version.LEGACY);