diff --git a/io.c b/io.c
index 21d6d12c9c..8838bba7e0 100644
--- a/io.c
+++ b/io.c
@@ -7456,7 +7456,7 @@ rb_io_ctl(VALUE io, VALUE req, VALUE arg, int io_p)
 		rb_str_resize(arg, len+1);
 	    }
 	    RSTRING_PTR(arg)[len] = 17;	/* a little sanity check here */
-	    narg = (long)RSTRING_PTR(arg);
+	    narg = (long)(SIGNED_VALUE)RSTRING_PTR(arg);
 	}
     }
     GetOpenFile(io, fptr);
diff --git a/parse.y b/parse.y
index 1cb37b41b8..71359a347b 100644
--- a/parse.y
+++ b/parse.y
@@ -8921,7 +8921,7 @@ new_args_gen(struct parser_params *parser, NODE *m, NODE *o, ID r, NODE *p, ID b
 }
 #endif /* !RIPPER */
 
-#define LVAR_USED (1UL << (sizeof(ID) * CHAR_BIT - 1))
+#define LVAR_USED ((ID)1 << (sizeof(ID) * CHAR_BIT - 1))
 
 static void
 warn_unused_var(struct parser_params *parser, struct local_vars *local)