1 files changed, 2 insertions, 1 deletions
diff --git a/io.c b/io.c
index be3984e7d7..8e0a4e78f3 100644
--- a/io.c
+++ b/io.c
@@ -4373,7 +4373,8 @@ rb_f_readlines(int argc, VALUE *argv)
 static VALUE
 rb_f_backquote(VALUE obj, VALUE str)
 {
-    VALUE port, result;
+    volatile VALUE port;
+    VALUE result;
     OpenFile *fptr;
 
     SafeStringValue(str);