diff --git a/include/SDL_stdinc.h b/include/SDL_stdinc.h
index 0035a357cf..8c22283af0 100644
--- a/include/SDL_stdinc.h
+++ b/include/SDL_stdinc.h
@@ -107,7 +107,7 @@
 # elif defined(__MRC__)
 void *alloca(unsigned);
 # else
-char *alloca();
+void *alloca(size_t);
 # endif
 #endif