diff --git a/test/test_delegate_observable.cpp b/test/test_delegate_observable.cpp
index 010786f6..d08d80ad 100644
--- a/test/test_delegate_observable.cpp
+++ b/test/test_delegate_observable.cpp
@@ -97,7 +97,7 @@ namespace
   };
 
   //*************************************************************************
-  ETL_CONSTEXPR14 Observable CreateObservable()
+  static ETL_CONSTEXPR14 Observable CreateObservable()
   {
     Observable observable;