diff --git a/src/tests/servers/app/workspace_activated/WorkspaceActivated.cpp b/src/tests/servers/app/workspace_activated/WorkspaceActivated.cpp
index 303df1bc8e..b8a4b9090a 100644
--- a/src/tests/servers/app/workspace_activated/WorkspaceActivated.cpp
+++ b/src/tests/servers/app/workspace_activated/WorkspaceActivated.cpp
@@ -8,6 +8,7 @@
 
 
 #include <Application.h>
+#include <String.h>
 #include <Window.h>
 #include <View.h>