diff --git a/ext/fiddle/closure.c b/ext/fiddle/closure.c
index 9a6c5ede3f..6770162b94 100644
--- a/ext/fiddle/closure.c
+++ b/ext/fiddle/closure.c
@@ -295,7 +295,7 @@ initialize_body(VALUE user_data)
     result = ffi_prep_closure_loc(pcl, cif, callback,
                                   (void *)(data->self), cl->code);
 #else
-    result = ffi_prep_closure(pcl, cif, callback, (void *)self);
+    result = ffi_prep_closure(pcl, cif, callback, (void *)(data->self));
     cl->code = (void *)pcl;
     i = mprotect(pcl, sizeof(*pcl), PROT_READ | PROT_EXEC);
     if (i) {