diff --git a/libpkgconf/cache.c b/libpkgconf/cache.c
index 4f3126c..03a3a32 100644
--- a/libpkgconf/cache.c
+++ b/libpkgconf/cache.c
@@ -15,8 +15,6 @@
 
 #include <libpkgconf/libpkgconf.h>
 
-static pkgconf_list_t pkg_cache = PKGCONF_LIST_INITIALIZER;
-
 /*
  * pkgconf_cache_lookup(id)
  *
@@ -25,16 +23,16 @@ static pkgconf_list_t pkg_cache = PKGCONF_LIST_INITIALIZER;
  * if present.
  */
 pkgconf_pkg_t *
-pkgconf_cache_lookup(const char *id)
+pkgconf_cache_lookup(const pkgconf_client_t *client, const char *id)
 {
 	pkgconf_node_t *node;
 
-	PKGCONF_FOREACH_LIST_ENTRY(pkg_cache.head, node)
+	PKGCONF_FOREACH_LIST_ENTRY(client->pkg_cache.head, node)
 	{
 		pkgconf_pkg_t *pkg = node->data;
 
 		if (!strcmp(pkg->id, id))
-			return pkgconf_pkg_ref(pkg);
+			return pkgconf_pkg_ref(client, pkg);
 	}
 
 	return NULL;
@@ -47,13 +45,13 @@ pkgconf_cache_lookup(const char *id)
  * the cache entry must be removed if the package is freed.
  */
 void
-pkgconf_cache_add(pkgconf_pkg_t *pkg)
+pkgconf_cache_add(pkgconf_client_t *client, pkgconf_pkg_t *pkg)
 {
 	if (pkg == NULL)
 		return;
 
-	pkgconf_pkg_ref(pkg);
-	pkgconf_node_insert(&pkg->cache_iter, pkg, &pkg_cache);
+	pkgconf_pkg_ref(client, pkg);
+	pkgconf_node_insert(&pkg->cache_iter, pkg, &client->pkg_cache);
 }
 
 /*
@@ -62,22 +60,24 @@ pkgconf_cache_add(pkgconf_pkg_t *pkg)
  * deletes a package from the cache entry.
  */
 void
-pkgconf_cache_remove(pkgconf_pkg_t *pkg)
+pkgconf_cache_remove(pkgconf_client_t *client, pkgconf_pkg_t *pkg)
 {
 	if (pkg == NULL)
 		return;
 
-	pkgconf_node_delete(&pkg->cache_iter, &pkg_cache);
+	pkgconf_node_delete(&pkg->cache_iter, &client->pkg_cache);
 }
 
 void
-pkgconf_cache_free(void)
+pkgconf_cache_free(pkgconf_client_t *client)
 {
 	pkgconf_node_t *iter, *iter2;
 
-	PKGCONF_FOREACH_LIST_ENTRY_SAFE(pkg_cache.head, iter2, iter)
+	PKGCONF_FOREACH_LIST_ENTRY_SAFE(client->pkg_cache.head, iter2, iter)
 	{
 		pkgconf_pkg_t *pkg = iter->data;
-		pkgconf_pkg_free(pkg);
+		pkgconf_pkg_free(client, pkg);
 	}
+
+	memset(&client->pkg_cache, 0, sizeof client->pkg_cache);
 }
diff --git a/libpkgconf/libpkgconf.h b/libpkgconf/libpkgconf.h
index 6b283d0..5021389 100644
--- a/libpkgconf/libpkgconf.h
+++ b/libpkgconf/libpkgconf.h
@@ -129,12 +129,13 @@ struct pkgconf_pkg_ {
 };
 
 typedef bool (*pkgconf_pkg_iteration_func_t)(const pkgconf_pkg_t *pkg, void *data);
-typedef void (*pkgconf_pkg_traverse_func_t)(const pkgconf_client_t *client, pkgconf_pkg_t *pkg, void *data, unsigned int flags);
-typedef bool (*pkgconf_queue_apply_func_t)(const pkgconf_client_t *client, pkgconf_pkg_t *world, void *data, int maxdepth, unsigned int flags);
+typedef void (*pkgconf_pkg_traverse_func_t)(pkgconf_client_t *client, pkgconf_pkg_t *pkg, void *data, unsigned int flags);
+typedef bool (*pkgconf_queue_apply_func_t)(pkgconf_client_t *client, pkgconf_pkg_t *world, void *data, int maxdepth, unsigned int flags);
 typedef bool (*pkgconf_error_handler_func_t)(const char *msg);
 
 struct pkgconf_client_ {
 	pkgconf_list_t dir_list;
+	pkgconf_list_t pkg_cache;
 
 #ifdef XXX_NOTYET
 	pkgconf_list_t filter_libdirs;
@@ -188,21 +189,21 @@ void pkgconf_client_free(pkgconf_client_t *client);
 bool pkgconf_error(const pkgconf_client_t *client, const char *format, ...) PRINTFLIKE(2, 3);
 bool pkgconf_default_error_handler(const char *msg);
 
-pkgconf_pkg_t *pkgconf_pkg_ref(pkgconf_pkg_t *pkg);
-void pkgconf_pkg_unref(pkgconf_pkg_t *pkg);
-void pkgconf_pkg_free(pkgconf_pkg_t *pkg);
+pkgconf_pkg_t *pkgconf_pkg_ref(const pkgconf_client_t *client, pkgconf_pkg_t *pkg);
+void pkgconf_pkg_unref(pkgconf_client_t *client, pkgconf_pkg_t *pkg);
+void pkgconf_pkg_free(pkgconf_client_t *client, pkgconf_pkg_t *pkg);
 pkgconf_pkg_t *pkgconf_pkg_find(pkgconf_client_t *client, const char *name, unsigned int flags);
-unsigned int pkgconf_pkg_traverse(const pkgconf_client_t *client, pkgconf_pkg_t *root, pkgconf_pkg_traverse_func_t func, void *data, int maxdepth, unsigned int flags);
-unsigned int pkgconf_pkg_verify_graph(const pkgconf_client_t *client, pkgconf_pkg_t *root, int depth, unsigned int flags);
-pkgconf_pkg_t *pkgconf_pkg_verify_dependency(const pkgconf_client_t *client, pkgconf_dependency_t *pkgdep, unsigned int flags, unsigned int *eflags);
+unsigned int pkgconf_pkg_traverse(pkgconf_client_t *client, pkgconf_pkg_t *root, pkgconf_pkg_traverse_func_t func, void *data, int maxdepth, unsigned int flags);
+unsigned int pkgconf_pkg_verify_graph(pkgconf_client_t *client, pkgconf_pkg_t *root, int depth, unsigned int flags);
+pkgconf_pkg_t *pkgconf_pkg_verify_dependency(pkgconf_client_t *client, pkgconf_dependency_t *pkgdep, unsigned int flags, unsigned int *eflags);
 const char *pkgconf_pkg_get_comparator(const pkgconf_dependency_t *pkgdep);
-int pkgconf_pkg_cflags(const pkgconf_client_t *client, pkgconf_pkg_t *root, pkgconf_list_t *list, int maxdepth, unsigned int flags);
-int pkgconf_pkg_libs(const pkgconf_client_t *client, pkgconf_pkg_t *root, pkgconf_list_t *list, int maxdepth, unsigned int flags);
+int pkgconf_pkg_cflags(pkgconf_client_t *client, pkgconf_pkg_t *root, pkgconf_list_t *list, int maxdepth, unsigned int flags);
+int pkgconf_pkg_libs(pkgconf_client_t *client, pkgconf_pkg_t *root, pkgconf_list_t *list, int maxdepth, unsigned int flags);
 pkgconf_pkg_comparator_t pkgconf_pkg_comparator_lookup_by_name(const char *name);
 pkgconf_pkg_t *pkgconf_builtin_pkg_get(const char *name);
 
 int pkgconf_compare_version(const char *a, const char *b);
-pkgconf_pkg_t *pkgconf_scan_all(const pkgconf_client_t *client, void *ptr, pkgconf_pkg_iteration_func_t func);
+pkgconf_pkg_t *pkgconf_scan_all(pkgconf_client_t *client, void *ptr, pkgconf_pkg_iteration_func_t func);
 void pkgconf_pkg_dir_list_build(pkgconf_client_t *client, unsigned int flags);
 
 /* parse.c */
@@ -239,16 +240,16 @@ void pkgconf_tuple_define_global(pkgconf_client_t *client, const char *kv);
 
 /* queue.c */
 void pkgconf_queue_push(pkgconf_list_t *list, const char *package);
-bool pkgconf_queue_compile(const pkgconf_client_t *client, pkgconf_pkg_t *world, pkgconf_list_t *list);
+bool pkgconf_queue_compile(pkgconf_client_t *client, pkgconf_pkg_t *world, pkgconf_list_t *list);
 void pkgconf_queue_free(pkgconf_list_t *list);
-bool pkgconf_queue_apply(const pkgconf_client_t *client, pkgconf_list_t *list, pkgconf_queue_apply_func_t func, int maxdepth, unsigned int flags, void *data);
-bool pkgconf_queue_validate(const pkgconf_client_t *client, pkgconf_list_t *list, int maxdepth, unsigned int flags);
+bool pkgconf_queue_apply(pkgconf_client_t *client, pkgconf_list_t *list, pkgconf_queue_apply_func_t func, int maxdepth, unsigned int flags, void *data);
+bool pkgconf_queue_validate(pkgconf_client_t *client, pkgconf_list_t *list, int maxdepth, unsigned int flags);
 
 /* cache.c */
-pkgconf_pkg_t *pkgconf_cache_lookup(const char *id);
-void pkgconf_cache_add(pkgconf_pkg_t *pkg);
-void pkgconf_cache_remove(pkgconf_pkg_t *pkg);
-void pkgconf_cache_free(void);
+pkgconf_pkg_t *pkgconf_cache_lookup(const pkgconf_client_t *client, const char *id);
+void pkgconf_cache_add(pkgconf_client_t *client, pkgconf_pkg_t *pkg);
+void pkgconf_cache_remove(pkgconf_client_t *client, pkgconf_pkg_t *pkg);
+void pkgconf_cache_free(pkgconf_client_t *client);
 
 /* audit.c */
 void pkgconf_audit_open_log(FILE *auditf);
diff --git a/libpkgconf/pkg.c b/libpkgconf/pkg.c
index 71bebea..7c9606f 100644
--- a/libpkgconf/pkg.c
+++ b/libpkgconf/pkg.c
@@ -259,16 +259,16 @@ pkgconf_pkg_new_from_file(const pkgconf_client_t *client, const char *filename,
 
 	pkgconf_dependency_add(&pkg->provides, pkg->id, pkg->version, PKGCONF_CMP_EQUAL);
 
-	return pkgconf_pkg_ref(pkg);
+	return pkgconf_pkg_ref(client, pkg);
 }
 
 void
-pkgconf_pkg_free(pkgconf_pkg_t *pkg)
+pkgconf_pkg_free(pkgconf_client_t *client, pkgconf_pkg_t *pkg)
 {
 	if (pkg == NULL || pkg->flags & PKGCONF_PKG_PROPF_VIRTUAL)
 		return;
 
-	pkgconf_cache_remove(pkg);
+	pkgconf_cache_remove(client, pkg);
 
 	pkgconf_dependency_free(&pkg->requires);
 	pkgconf_dependency_free(&pkg->requires_private);
@@ -307,18 +307,20 @@ pkgconf_pkg_free(pkgconf_pkg_t *pkg)
 }
 
 pkgconf_pkg_t *
-pkgconf_pkg_ref(pkgconf_pkg_t *pkg)
+pkgconf_pkg_ref(const pkgconf_client_t *client, pkgconf_pkg_t *pkg)
 {
+	(void) client;
+
 	pkg->refcount++;
 	return pkg;
 }
 
 void
-pkgconf_pkg_unref(pkgconf_pkg_t *pkg)
+pkgconf_pkg_unref(pkgconf_client_t *client, pkgconf_pkg_t *pkg)
 {
 	pkg->refcount--;
 	if (pkg->refcount <= 0)
-		pkgconf_pkg_free(pkg);
+		pkgconf_pkg_free(client, pkg);
 }
 
 static inline pkgconf_pkg_t *
@@ -344,7 +346,7 @@ pkgconf_pkg_try_specific_path(const pkgconf_client_t *client, const char *path,
 }
 
 static pkgconf_pkg_t *
-pkgconf_pkg_scan_dir(const pkgconf_client_t *client, const char *path, void *data, pkgconf_pkg_iteration_func_t func)
+pkgconf_pkg_scan_dir(pkgconf_client_t *client, const char *path, void *data, pkgconf_pkg_iteration_func_t func)
 {
 	DIR *dir;
 	struct dirent *dirent;
@@ -382,7 +384,7 @@ pkgconf_pkg_scan_dir(const pkgconf_client_t *client, const char *path, void *dat
 				goto out;
 			}
 
-			pkgconf_pkg_unref(pkg);
+			pkgconf_pkg_unref(client, pkg);
 		}
 	}
 
@@ -392,7 +394,7 @@ out:
 }
 
 pkgconf_pkg_t *
-pkgconf_scan_all(const pkgconf_client_t *client, void *data, pkgconf_pkg_iteration_func_t func)
+pkgconf_scan_all(pkgconf_client_t *client, void *data, pkgconf_pkg_iteration_func_t func)
 {
 	pkgconf_node_t *n;
 	pkgconf_pkg_t *pkg;
@@ -474,7 +476,7 @@ pkgconf_pkg_find(pkgconf_client_t *client, const char *name, unsigned int flags)
 	/* check cache */
 	if (!(flags & PKGCONF_PKG_PKGF_NO_CACHE))
 	{
-		if ((pkg = pkgconf_cache_lookup(name)) != NULL)
+		if ((pkg = pkgconf_cache_lookup(client, name)) != NULL)
 		{
 			pkg->flags |= PKGCONF_PKG_PROPF_CACHED;
 			return pkg;
@@ -498,7 +500,7 @@ pkgconf_pkg_find(pkgconf_client_t *client, const char *name, unsigned int flags)
 #endif
 
 out:
-	pkgconf_cache_add(pkg);
+	pkgconf_cache_add(client, pkg);
 
 	return pkg;
 }
@@ -960,7 +962,7 @@ pkgconf_pkg_scan_provides_entry(const pkgconf_pkg_t *pkg, const pkgconf_pkg_scan
  * scan all available packages to see if a Provides rule matches the pkgdep.
  */
 static pkgconf_pkg_t *
-pkgconf_pkg_scan_providers(const pkgconf_client_t *client, pkgconf_dependency_t *pkgdep, unsigned int flags, unsigned int *eflags)
+pkgconf_pkg_scan_providers(pkgconf_client_t *client, pkgconf_dependency_t *pkgdep, unsigned int flags, unsigned int *eflags)
 {
 	pkgconf_pkg_t *pkg;
 	pkgconf_pkg_scan_providers_ctx_t ctx = {
@@ -985,7 +987,7 @@ pkgconf_pkg_scan_providers(const pkgconf_client_t *client, pkgconf_dependency_t
  * return the appropriate pkgconf_pkg_t object, else NULL.
  */
 pkgconf_pkg_t *
-pkgconf_pkg_verify_dependency(const pkgconf_client_t *client, pkgconf_dependency_t *pkgdep, unsigned int flags, unsigned int *eflags)
+pkgconf_pkg_verify_dependency(pkgconf_client_t *client, pkgconf_dependency_t *pkgdep, unsigned int flags, unsigned int *eflags)
 {
 	pkgconf_pkg_t *pkg = NULL;
 
@@ -1025,13 +1027,13 @@ pkgconf_pkg_verify_dependency(const pkgconf_client_t *client, pkgconf_dependency
  * pkgconf_pkg_traverse().
  */
 unsigned int
-pkgconf_pkg_verify_graph(const pkgconf_client_t *client, pkgconf_pkg_t *root, int depth, unsigned int flags)
+pkgconf_pkg_verify_graph(pkgconf_client_t *client, pkgconf_pkg_t *root, int depth, unsigned int flags)
 {
 	return pkgconf_pkg_traverse(client, root, NULL, NULL, depth, flags);
 }
 
 static unsigned int
-pkgconf_pkg_report_graph_error(const pkgconf_client_t *client, pkgconf_pkg_t *parent, pkgconf_pkg_t *pkg, pkgconf_dependency_t *node, unsigned int eflags)
+pkgconf_pkg_report_graph_error(pkgconf_client_t *client, pkgconf_pkg_t *parent, pkgconf_pkg_t *pkg, pkgconf_dependency_t *node, unsigned int eflags)
 {
 	static bool already_sent_notice = false;
 
@@ -1059,13 +1061,13 @@ pkgconf_pkg_report_graph_error(const pkgconf_client_t *client, pkgconf_pkg_t *pa
 	}
 
 	if (pkg != NULL)
-		pkgconf_pkg_unref(pkg);
+		pkgconf_pkg_unref(client, pkg);
 
 	return eflags;
 }
 
 static inline unsigned int
-pkgconf_pkg_walk_list(const pkgconf_client_t *client,
+pkgconf_pkg_walk_list(pkgconf_client_t *client,
 	pkgconf_pkg_t *parent,
 	pkgconf_list_t *deplist,
 	pkgconf_pkg_traverse_func_t func,
@@ -1098,7 +1100,7 @@ pkgconf_pkg_walk_list(const pkgconf_client_t *client,
 
 		if (pkgdep->flags & PKGCONF_PKG_PROPF_SEEN)
 		{
-			pkgconf_pkg_unref(pkgdep);
+			pkgconf_pkg_unref(client, pkgdep);
 			continue;
 		}
 
@@ -1107,14 +1109,14 @@ pkgconf_pkg_walk_list(const pkgconf_client_t *client,
 		pkgdep->flags |= PKGCONF_PKG_PROPF_SEEN;
 		eflags |= pkgconf_pkg_traverse(client, pkgdep, func, data, depth - 1, flags);
 		pkgdep->flags &= ~PKGCONF_PKG_PROPF_SEEN;
-		pkgconf_pkg_unref(pkgdep);
+		pkgconf_pkg_unref(client, pkgdep);
 	}
 
 	return eflags;
 }
 
 static inline unsigned int
-pkgconf_pkg_walk_conflicts_list(const pkgconf_client_t *client,
+pkgconf_pkg_walk_conflicts_list(pkgconf_client_t *client,
 	pkgconf_pkg_t *root, pkgconf_list_t *deplist, unsigned int flags)
 {
 	unsigned int eflags;
@@ -1144,12 +1146,12 @@ pkgconf_pkg_walk_conflicts_list(const pkgconf_client_t *client,
 				pkgconf_error(client, "It may be possible to ignore this conflict and continue, try the\n");
 				pkgconf_error(client, "PKG_CONFIG_IGNORE_CONFLICTS environment variable.\n");
 
-				pkgconf_pkg_unref(pkgdep);
+				pkgconf_pkg_unref(client, pkgdep);
 
 				return PKGCONF_PKG_ERRF_PACKAGE_CONFLICT;
 			}
 
-			pkgconf_pkg_unref(pkgdep);
+			pkgconf_pkg_unref(client, pkgdep);
 		}
 	}
 
@@ -1162,7 +1164,7 @@ pkgconf_pkg_walk_conflicts_list(const pkgconf_client_t *client,
  * walk the dependency graph up to maxdepth levels.  -1 means infinite recursion.
  */
 unsigned int
-pkgconf_pkg_traverse(const pkgconf_client_t *client,
+pkgconf_pkg_traverse(pkgconf_client_t *client,
 	pkgconf_pkg_t *root,
 	pkgconf_pkg_traverse_func_t func,
 	void *data,
@@ -1203,7 +1205,7 @@ pkgconf_pkg_traverse(const pkgconf_client_t *client,
 }
 
 static void
-pkgconf_pkg_cflags_collect(const pkgconf_client_t *client, pkgconf_pkg_t *pkg, void *data, unsigned int flags)
+pkgconf_pkg_cflags_collect(pkgconf_client_t *client, pkgconf_pkg_t *pkg, void *data, unsigned int flags)
 {
 	pkgconf_list_t *list = data;
 	pkgconf_node_t *node;
@@ -1218,7 +1220,7 @@ pkgconf_pkg_cflags_collect(const pkgconf_client_t *client, pkgconf_pkg_t *pkg, v
 }
 
 static void
-pkgconf_pkg_cflags_private_collect(const pkgconf_client_t *client, pkgconf_pkg_t *pkg, void *data, unsigned int flags)
+pkgconf_pkg_cflags_private_collect(pkgconf_client_t *client, pkgconf_pkg_t *pkg, void *data, unsigned int flags)
 {
 	pkgconf_list_t *list = data;
 	pkgconf_node_t *node;
@@ -1234,7 +1236,7 @@ pkgconf_pkg_cflags_private_collect(const pkgconf_client_t *client, pkgconf_pkg_t
 }
 
 int
-pkgconf_pkg_cflags(const pkgconf_client_t *client, pkgconf_pkg_t *root, pkgconf_list_t *list, int maxdepth, unsigned int flags)
+pkgconf_pkg_cflags(pkgconf_client_t *client, pkgconf_pkg_t *root, pkgconf_list_t *list, int maxdepth, unsigned int flags)
 {
 	int eflag;
 
@@ -1253,7 +1255,7 @@ pkgconf_pkg_cflags(const pkgconf_client_t *client, pkgconf_pkg_t *root, pkgconf_
 }
 
 static void
-pkgconf_pkg_libs_collect(const pkgconf_client_t *client, pkgconf_pkg_t *pkg, void *data, unsigned int flags)
+pkgconf_pkg_libs_collect(pkgconf_client_t *client, pkgconf_pkg_t *pkg, void *data, unsigned int flags)
 {
 	pkgconf_list_t *list = data;
 	pkgconf_node_t *node;
@@ -1277,7 +1279,7 @@ pkgconf_pkg_libs_collect(const pkgconf_client_t *client, pkgconf_pkg_t *pkg, voi
 }
 
 int
-pkgconf_pkg_libs(const pkgconf_client_t *client, pkgconf_pkg_t *root, pkgconf_list_t *list, int maxdepth, unsigned int flags)
+pkgconf_pkg_libs(pkgconf_client_t *client, pkgconf_pkg_t *root, pkgconf_list_t *list, int maxdepth, unsigned int flags)
 {
 	int eflag;
 
diff --git a/libpkgconf/queue.c b/libpkgconf/queue.c
index c1dbfc3..c6bef99 100644
--- a/libpkgconf/queue.c
+++ b/libpkgconf/queue.c
@@ -30,7 +30,7 @@ pkgconf_queue_push(pkgconf_list_t *list, const char *package)
 }
 
 bool
-pkgconf_queue_compile(const pkgconf_client_t *client, pkgconf_pkg_t *world, pkgconf_list_t *list)
+pkgconf_queue_compile(pkgconf_client_t *client, pkgconf_pkg_t *world, pkgconf_list_t *list)
 {
 	pkgconf_node_t *iter;
 
@@ -60,7 +60,7 @@ pkgconf_queue_free(pkgconf_list_t *list)
 }
 
 static inline unsigned int
-pkgconf_queue_verify(const pkgconf_client_t *client, pkgconf_pkg_t *world, pkgconf_list_t *list, int maxdepth, unsigned int flags)
+pkgconf_queue_verify(pkgconf_client_t *client, pkgconf_pkg_t *world, pkgconf_list_t *list, int maxdepth, unsigned int flags)
 {
 	if (!pkgconf_queue_compile(client, world, list))
 		return PKGCONF_PKG_ERRF_DEPGRAPH_BREAK;
@@ -69,7 +69,7 @@ pkgconf_queue_verify(const pkgconf_client_t *client, pkgconf_pkg_t *world, pkgco
 }
 
 bool
-pkgconf_queue_apply(const pkgconf_client_t *client, pkgconf_list_t *list, pkgconf_queue_apply_func_t func, int maxdepth, unsigned int flags, void *data)
+pkgconf_queue_apply(pkgconf_client_t *client, pkgconf_list_t *list, pkgconf_queue_apply_func_t func, int maxdepth, unsigned int flags, void *data)
 {
 	pkgconf_pkg_t world = {
 		.id = "virtual:world",
@@ -86,17 +86,17 @@ pkgconf_queue_apply(const pkgconf_client_t *client, pkgconf_list_t *list, pkgcon
 
 	if (!func(client, &world, data, maxdepth, flags))
 	{
-		pkgconf_pkg_free(&world);
+		pkgconf_pkg_free(client, &world);
 		return false;
 	}
 
-	pkgconf_pkg_free(&world);
+	pkgconf_pkg_free(client, &world);
 
 	return true;
 }
 
 bool
-pkgconf_queue_validate(const pkgconf_client_t *client, pkgconf_list_t *list, int maxdepth, unsigned int flags)
+pkgconf_queue_validate(pkgconf_client_t *client, pkgconf_list_t *list, int maxdepth, unsigned int flags)
 {
 	bool retval = true;
 	pkgconf_pkg_t world = {
@@ -112,7 +112,7 @@ pkgconf_queue_validate(const pkgconf_client_t *client, pkgconf_list_t *list, int
 	if (pkgconf_queue_verify(client, &world, list, maxdepth, flags) != PKGCONF_PKG_ERRF_OK)
 		retval = false;
 
-	pkgconf_pkg_free(&world);
+	pkgconf_pkg_free(client, &world);
 
 	return retval;
 }
diff --git a/main.c b/main.c
index 17c6990..9effa8b 100644
--- a/main.c
+++ b/main.c
@@ -184,7 +184,7 @@ print_libs(pkgconf_list_t *list)
 }
 
 static void
-print_modversion(const pkgconf_client_t *client, pkgconf_pkg_t *pkg, void *unused, unsigned int flags)
+print_modversion(pkgconf_client_t *client, pkgconf_pkg_t *pkg, void *unused, unsigned int flags)
 {
 	(void) client;
 	(void) unused;
@@ -195,7 +195,7 @@ print_modversion(const pkgconf_client_t *client, pkgconf_pkg_t *pkg, void *unuse
 }
 
 static void
-print_variables(const pkgconf_client_t *client, pkgconf_pkg_t *pkg, void *unused, unsigned int flags)
+print_variables(pkgconf_client_t *client, pkgconf_pkg_t *pkg, void *unused, unsigned int flags)
 {
 	pkgconf_node_t *node;
 	(void) client;
@@ -265,7 +265,7 @@ print_provides(pkgconf_pkg_t *pkg)
 }
 
 static bool
-apply_provides(const pkgconf_client_t *client, pkgconf_pkg_t *world, void *unused, int maxdepth, unsigned int flags)
+apply_provides(pkgconf_client_t *client, pkgconf_pkg_t *world, void *unused, int maxdepth, unsigned int flags)
 {
 	pkgconf_node_t *iter;
 	(void) unused;
@@ -279,14 +279,14 @@ apply_provides(const pkgconf_client_t *client, pkgconf_pkg_t *world, void *unuse
 		pkg = pkgconf_pkg_verify_dependency(client, dep, flags, NULL);
 		print_provides(pkg);
 
-		pkgconf_pkg_free(pkg);
+		pkgconf_pkg_free(&pkg_client, pkg);
 	}
 
 	return true;
 }
 
 static void
-print_digraph_node(const pkgconf_client_t *client, pkgconf_pkg_t *pkg, void *unused, unsigned int flags)
+print_digraph_node(pkgconf_client_t *client, pkgconf_pkg_t *pkg, void *unused, unsigned int flags)
 {
 	pkgconf_node_t *node;
 	(void) client;
@@ -304,7 +304,7 @@ print_digraph_node(const pkgconf_client_t *client, pkgconf_pkg_t *pkg, void *unu
 }
 
 static bool
-apply_digraph(const pkgconf_client_t *client, pkgconf_pkg_t *world, void *unused, int maxdepth, unsigned int flags)
+apply_digraph(pkgconf_client_t *client, pkgconf_pkg_t *world, void *unused, int maxdepth, unsigned int flags)
 {
 	int eflag;
 
@@ -322,7 +322,7 @@ apply_digraph(const pkgconf_client_t *client, pkgconf_pkg_t *world, void *unused
 }
 
 static bool
-apply_modversion(const pkgconf_client_t *client, pkgconf_pkg_t *world, void *unused, int maxdepth, unsigned int flags)
+apply_modversion(pkgconf_client_t *client, pkgconf_pkg_t *world, void *unused, int maxdepth, unsigned int flags)
 {
 	int eflag;
 
@@ -335,7 +335,7 @@ apply_modversion(const pkgconf_client_t *client, pkgconf_pkg_t *world, void *unu
 }
 
 static bool
-apply_variables(const pkgconf_client_t *client, pkgconf_pkg_t *world, void *unused, int maxdepth, unsigned int flags)
+apply_variables(pkgconf_client_t *client, pkgconf_pkg_t *world, void *unused, int maxdepth, unsigned int flags)
 {
 	int eflag;
 
@@ -353,7 +353,7 @@ typedef struct {
 } var_request_t;
 
 static void
-print_variable(const pkgconf_client_t *client, pkgconf_pkg_t *pkg, void *data, unsigned int flags)
+print_variable(pkgconf_client_t *client, pkgconf_pkg_t *pkg, void *data, unsigned int flags)
 {
 	var_request_t *req = data;
 	const char *var;
@@ -385,7 +385,7 @@ print_variable(const pkgconf_client_t *client, pkgconf_pkg_t *pkg, void *data, u
 }
 
 static bool
-apply_variable(const pkgconf_client_t *client, pkgconf_pkg_t *world, void *variable, int maxdepth, unsigned int flags)
+apply_variable(pkgconf_client_t *client, pkgconf_pkg_t *world, void *variable, int maxdepth, unsigned int flags)
 {
 	int eflag;
 
@@ -404,7 +404,7 @@ apply_variable(const pkgconf_client_t *client, pkgconf_pkg_t *world, void *varia
 }
 
 static bool
-apply_cflags(const pkgconf_client_t *client, pkgconf_pkg_t *world, void *list_head, int maxdepth, unsigned int flags)
+apply_cflags(pkgconf_client_t *client, pkgconf_pkg_t *world, void *list_head, int maxdepth, unsigned int flags)
 {
 	pkgconf_list_t *list = list_head;
 	int eflag;
@@ -424,7 +424,7 @@ apply_cflags(const pkgconf_client_t *client, pkgconf_pkg_t *world, void *list_he
 }
 
 static bool
-apply_libs(const pkgconf_client_t *client, pkgconf_pkg_t *world, void *list_head, int maxdepth, unsigned int flags)
+apply_libs(pkgconf_client_t *client, pkgconf_pkg_t *world, void *list_head, int maxdepth, unsigned int flags)
 {
 	pkgconf_list_t *list = list_head;
 	int eflag;
@@ -444,7 +444,7 @@ apply_libs(const pkgconf_client_t *client, pkgconf_pkg_t *world, void *list_head
 }
 
 static bool
-apply_requires(const pkgconf_client_t *client, pkgconf_pkg_t *world, void *unused, int maxdepth, unsigned int flags)
+apply_requires(pkgconf_client_t *client, pkgconf_pkg_t *world, void *unused, int maxdepth, unsigned int flags)
 {
 	pkgconf_node_t *iter;
 	(void) unused;
@@ -458,14 +458,14 @@ apply_requires(const pkgconf_client_t *client, pkgconf_pkg_t *world, void *unuse
 		pkg = pkgconf_pkg_verify_dependency(client, dep, flags, NULL);
 		print_requires(pkg);
 
-		pkgconf_pkg_free(pkg);
+		pkgconf_pkg_free(&pkg_client, pkg);
 	}
 
 	return true;
 }
 
 static bool
-apply_requires_private(const pkgconf_client_t *client, pkgconf_pkg_t *world, void *unused, int maxdepth, unsigned int flags)
+apply_requires_private(pkgconf_client_t *client, pkgconf_pkg_t *world, void *unused, int maxdepth, unsigned int flags)
 {
 	pkgconf_node_t *iter;
 	(void) unused;
@@ -479,13 +479,13 @@ apply_requires_private(const pkgconf_client_t *client, pkgconf_pkg_t *world, voi
 		pkg = pkgconf_pkg_verify_dependency(client, dep, flags | PKGCONF_PKG_PKGF_SEARCH_PRIVATE, NULL);
 		print_requires_private(pkg);
 
-		pkgconf_pkg_free(pkg);
+		pkgconf_pkg_free(&pkg_client, pkg);
 	}
 	return true;
 }
 
 static void
-check_uninstalled(const pkgconf_client_t *client, pkgconf_pkg_t *pkg, void *data, unsigned int flags)
+check_uninstalled(pkgconf_client_t *client, pkgconf_pkg_t *pkg, void *data, unsigned int flags)
 {
 	int *retval = data;
 	(void) client;
@@ -496,7 +496,7 @@ check_uninstalled(const pkgconf_client_t *client, pkgconf_pkg_t *pkg, void *data
 }
 
 static bool
-apply_uninstalled(const pkgconf_client_t *client, pkgconf_pkg_t *world, void *data, int maxdepth, unsigned int flags)
+apply_uninstalled(pkgconf_client_t *client, pkgconf_pkg_t *world, void *data, int maxdepth, unsigned int flags)
 {
 	int eflag;
 
@@ -509,7 +509,7 @@ apply_uninstalled(const pkgconf_client_t *client, pkgconf_pkg_t *world, void *da
 }
 
 static void
-print_graph_node(const pkgconf_client_t *client, pkgconf_pkg_t *pkg, void *data, unsigned int flags)
+print_graph_node(pkgconf_client_t *client, pkgconf_pkg_t *pkg, void *data, unsigned int flags)
 {
 	pkgconf_node_t *n;
 
@@ -541,7 +541,7 @@ print_graph_node(const pkgconf_client_t *client, pkgconf_pkg_t *pkg, void *data,
 }
 
 static bool
-apply_simulate(const pkgconf_client_t *client, pkgconf_pkg_t *world, void *data, int maxdepth, unsigned int flags)
+apply_simulate(pkgconf_client_t *client, pkgconf_pkg_t *world, void *data, int maxdepth, unsigned int flags)
 {
 	int eflag;
 
@@ -1111,7 +1111,6 @@ out_println:
 
 out:
 	pkgconf_client_deinit(&pkg_client);
-	pkgconf_cache_free();
 
 	if (logfile_out != NULL)
 		fclose(logfile_out);