diff --git a/libctf/ChangeLog b/libctf/ChangeLog
index 779f7b1cc8..4a10f63d00 100644
--- a/libctf/ChangeLog
+++ b/libctf/ChangeLog
@@ -1,3 +1,7 @@
+2020-07-22  Nick Alcock  <nick.alcock@oracle.com>
+
+	ctf-decls.h (ctf_qsort_compar_thunk): Fix arg passing.
+
 2020-07-22  Nick Alcock  <nick.alcock@oracle.com>
 
 	* ctf-impl.h (ctf_next_hkv_t): New, kv-pairs passed to
diff --git a/libctf/ctf-decls.h b/libctf/ctf-decls.h
index 51041c592f..c47a72e722 100644
--- a/libctf/ctf-decls.h
+++ b/libctf/ctf-decls.h
@@ -46,7 +46,7 @@ ctf_qsort_compar_thunk (void *arg, const void *a, const void *b)
 {
   struct ctf_qsort_arg *qsort_arg = (struct ctf_qsort_arg *) arg;
 
-  return qsort_arg->compar (a, b, arg);
+  return qsort_arg->compar (a, b, qsort_arg->arg);
 }
 
 static inline void