1 files changed, 2 insertions, 1 deletions
diff --git a/io.c b/io.c
index 826285842c..626e9b8c62 100644
--- a/io.c
+++ b/io.c
@@ -4513,7 +4513,8 @@ static VALUE
 rb_f_backquote(obj, str)
     VALUE obj, str;
 {
-    VALUE port, result;
+    volatile VALUE port;
+    VALUE result;
     OpenFile *fptr;
 
     SafeStringValue(str);