diff -up asc-2.8.0.1/source/libs/sdlmm/src/sdlmm_basesurface.h~ asc-2.8.0.1/source/libs/sdlmm/src/sdlmm_basesurface.h
--- asc-2.8.0.1/source/libs/sdlmm/src/sdlmm_basesurface.h~	2018-02-27 01:20:08.000000000 +0100
+++ asc-2.8.0.1/source/libs/sdlmm/src/sdlmm_basesurface.h	2021-07-29 22:00:31.785819930 +0200
@@ -139,7 +139,7 @@ namespace SDLmm {
     const void *pixels() const { return GetSurface()->pixels; }
 
     //! Returns the hardware-specific surface info.
-    struct private_hwdata *hwdata() const { return GetSurface()->hwdata; }
+    struct private_hwdata *hwdata() const { return (struct private_hwdata *)(GetSurface()->hwdata); }
     //@}
 
     //! Set the pixel to the color