diff --git a/compiler/old-rt/core.lisp b/compiler/old-rt/core.lisp
index bf65e8d1da08b49774916cb4797e818d87ffbc5f..0d6aa7da059e4208f147a2e620c4beda60377411 100644
--- a/compiler/old-rt/core.lisp
+++ b/compiler/old-rt/core.lisp
@@ -142,7 +142,7 @@
 			    (core-function-or-lose (cdr const) object)))
 	       (:label
 		(%primitive header-set code-obj i
-			    (+ (label-location (cdr entry))
+			    (+ (label-location (cdr const))
 				clc::i-vector-header-size))))))))))
   (undefined-value))