diff --git a/include/SDL3/SDL_stdinc.h b/include/SDL3/SDL_stdinc.h
index 8121bf2a9..b8ef87490 100644
--- a/include/SDL3/SDL_stdinc.h
+++ b/include/SDL3/SDL_stdinc.h
@@ -66,7 +66,7 @@
 #  elif defined(__MRC__)
 void *alloca(unsigned);
 #  else
-char *alloca();
+void *alloca(size_t);
 #  endif
 # endif
 #endif