--- a/archival/libipkg/pkg.c
+++ b/archival/libipkg/pkg.c
@@ -1139,8 +1139,12 @@
      return 0;
 }
 
-int pkg_name_version_and_architecture_compare(pkg_t *a, pkg_t *b)
+int pkg_name_version_and_architecture_compare(const void *pkg_a, const void *pkg_b)
 {
+     pkg_t * const *p1 = pkg_a;
+     pkg_t * const *p2 = pkg_b;
+     const pkg_t *a = *p1;
+     const pkg_t *b = *p2;
      int namecmp;
      int vercmp;
      if (!a->name || !b->name) {
@@ -1167,8 +1171,12 @@
      return 0;
 }
 
-int abstract_pkg_name_compare(abstract_pkg_t *a, abstract_pkg_t *b)
+int abstract_pkg_name_compare(const void *apkg_a, const void *apkg_b)
 {
+     abstract_pkg_t * const *ap1 = apkg_a;
+     abstract_pkg_t * const *ap2 = apkg_b;
+     const abstract_pkg_t *a = *ap1;
+     const abstract_pkg_t *b = *ap2;
      if (!a->name || !b->name) {
        fprintf(stderr, "abstract_pkg_name_compare: a=%p a->name=%p b=%p b->name=%p\n",
 	       a, a->name, b, b->name);
--- a/archival/libipkg/pkg.h
+++ b/archival/libipkg/pkg.h
@@ -191,8 +191,8 @@
 char *pkg_version_str_alloc(pkg_t *pkg);
 
 int pkg_compare_versions(const pkg_t *pkg, const pkg_t *ref_pkg);
-int pkg_name_version_and_architecture_compare(pkg_t *a, pkg_t *b);
-int abstract_pkg_name_compare(abstract_pkg_t *a, abstract_pkg_t *b);
+int pkg_name_version_and_architecture_compare(const void *pkg_a, const void *pkg_b);
+int abstract_pkg_name_compare(const void *apkg_a, const void *apkg_b);
 
 char * pkg_formatted_info(pkg_t *pkg );
 char * pkg_formatted_field(pkg_t *pkg, const char *field );