diff --git a/nac3artiq/src/lib.rs b/nac3artiq/src/lib.rs
index 3b4df2e1..205ee5c5 100644
--- a/nac3artiq/src/lib.rs
+++ b/nac3artiq/src/lib.rs
@@ -903,7 +903,7 @@ impl Nac3 {
                 }))),
             ),
             {
-                let arg_ty = unifier.get_dummy_var();
+                let arg_ty = unifier.get_fresh_var(Some("T".into()), None);
 
                 (
                     "core_log".into(),
@@ -925,7 +925,7 @@ impl Nac3 {
                 )
             },
             {
-                let arg_ty = unifier.get_dummy_var();
+                let arg_ty = unifier.get_fresh_var(Some("T".into()), None);
 
                 (
                     "rtio_log".into(),