diff --git a/src/machine/system_calls.rs b/src/machine/system_calls.rs
index 3a6c321b..edd08cb5 100644
--- a/src/machine/system_calls.rs
+++ b/src/machine/system_calls.rs
@@ -925,7 +925,7 @@ impl MachineState {
             &mut self.lifted_heap,
         );
 
-        let pstr_boundary = copy_term(copy_ball_term, copy_target, AttrVarPolicy::DeepCopy)?;
+        let pstr_boundary = copy_term(copy_ball_term, copy_target, AttrVarPolicy::StripAttributes)?;
 
         Ok(FindallCopyInfo {
             offset: threshold + lh_offset + 2,