diff --git a/include/gdi.h b/include/gdi.h
index 35ea01a4..eb22baad 100644
--- a/include/gdi.h
+++ b/include/gdi.h
@@ -8018,7 +8018,7 @@ MG_EXPORT HDC GUIAPI InitSlaveScreenEx (const char* name, const char* mode, int
  *
  * \return Valid handle on success, HDC_INVALID on failure.
  */
-inline HDC InitSlaveScreen (const char* name, const char* mode)
+static inline HDC InitSlaveScreen (const char* name, const char* mode)
 {
     return InitSlaveScreenEx(name, mode, GDCAP_DPI_DEFAULT);
 }