diff --git a/dlls/infosoft/infosoft_main.c b/dlls/infosoft/infosoft_main.c
index 619eca21a6a..518e44c860e 100644
--- a/dlls/infosoft/infosoft_main.c
+++ b/dlls/infosoft/infosoft_main.c
@@ -56,7 +56,7 @@ BOOL WINAPI DllMain(HINSTANCE hInstDLL, DWORD fdwReason, LPVOID lpv)
     return TRUE;
 }
 
-extern HRESULT WINAPI wb_Constructor(IUnknown*, REFIID, LPVOID *);
+DECLSPEC_HIDDEN extern HRESULT WINAPI wb_Constructor(IUnknown*, REFIID, LPVOID *);
 
 typedef HRESULT (CALLBACK *LPFNCREATEINSTANCE)(IUnknown*, REFIID, LPVOID*);
 
diff --git a/dlls/infosoft/wordbreaker.c b/dlls/infosoft/wordbreaker.c
index 69e2eb88662..17897668e24 100644
--- a/dlls/infosoft/wordbreaker.c
+++ b/dlls/infosoft/wordbreaker.c
@@ -183,7 +183,7 @@ static const IWordBreakerVtbl wordbreaker_vtbl =
     wb_GetLicenseToUse,
 };
 
-HRESULT WINAPI wb_Constructor(IUnknown* pUnkOuter, REFIID riid, LPVOID *ppvObject)
+DECLSPEC_HIDDEN HRESULT WINAPI wb_Constructor(IUnknown* pUnkOuter, REFIID riid, LPVOID *ppvObject)
 {
     wordbreaker_impl *This;
     IWordBreaker *wb;