diff -r 07176d5b81d5 -r 6afba546f0e5 src/HOL/Proofs/Extraction/Higman_Extraction.thy
--- a/src/HOL/Proofs/Extraction/Higman_Extraction.thy	Tue Jan 02 16:17:13 2018 +0100
+++ b/src/HOL/Proofs/Extraction/Higman_Extraction.thy	Tue Jan 02 16:40:54 2018 +0100
@@ -6,7 +6,7 @@
 subsection \<open>Extracting the program\<close>
 
 theory Higman_Extraction
-imports Higman "HOL-Library.Old_Datatype" "HOL-Library.Open_State_Syntax"
+imports Higman "HOL-Library.Realizers" "HOL-Library.Open_State_Syntax"
 begin
 
 declare R.induct [ind_realizer]