diff -r 6342cbbd1922 -r e19825a1430a src/list.c
--- a/src/list.c	Wed Oct 18 12:03:44 2017 +0200
+++ b/src/list.c	Wed Oct 18 14:23:57 2017 +0200
@@ -241,7 +241,7 @@
 }
 
 static UcxList *ucx_list_sort_merge(int length,
-        UcxList* restrict ls, UcxList* restrict le, UcxList* restrict re,
+        UcxList* ls, UcxList* le, UcxList* re,
         cmp_func fnc, void* data) {
 
     UcxList** sorted = (UcxList**) malloc(sizeof(UcxList*)*length);
@@ -291,7 +291,7 @@
     UcxList *lc;
     int ln = 1;
 
-    UcxList *restrict ls = l, *restrict le, *restrict re;
+    UcxList *ls = l, *le, *re;
     
     // check how many elements are already sorted
     lc = ls;