diff --git a/zipkin-server/src/main/resources/zipkin-server-shared.yml b/zipkin-server/src/main/resources/zipkin-server-shared.yml
index ed1a300f49b..3d26a33f914 100644
--- a/zipkin-server/src/main/resources/zipkin-server-shared.yml
+++ b/zipkin-server/src/main/resources/zipkin-server-shared.yml
@@ -46,7 +46,7 @@ zipkin:
   storage:
     strict-trace-id: ${STRICT_TRACE_ID:true}
     search-enabled: ${SEARCH_ENABLED:true}
-    autocompleteKeys: ${AUTOCOMPLETEKEYS}
+    autocompleteKeys: ${AUTOCOMPLETEKEYS:}
     type: ${STORAGE_TYPE:mem}
     mem:
       # Maximum number of spans to keep in memory.  When exceeded, oldest traces (and their spans) will be purged.