diff --git a/acconfig.h b/acconfig.h
index a7ed7b9e6..2d0aaea51 100644
--- a/acconfig.h
+++ b/acconfig.h
@@ -32,7 +32,7 @@
 #endif
 
 #define RCSID(msg) \
-static /**/const char *const rcsid[] = { (char *)rcsid, "\100(#)" msg }
+static /**/const char *const rcsid[] = { (const char *)rcsid, "\100(#)" msg }
 
 #undef PROTOTYPES