diff --git a/test/test_library.cpp b/test/test_library.cpp
index b984cfd..3a5c48b 100644
--- a/test/test_library.cpp
+++ b/test/test_library.cpp
@@ -19,6 +19,7 @@
 namespace test_library
 {
 
+RCPPUTILS_PUBLIC
 int add_one(int x)
 {
   return x + 1;